The Three Types of Cataracts and What Vision Looks Like with Them

A retired schoolteacher once described the moment she knew something had changed: she repainted her kitchen a crisp white, stood back, and thought the store had sold her cream. Her daughter saw white. She saw butter. Neither of them was wrong about the paint. One of them was looking through a lens that had quietly turned the color of weak tea.

That is what makes cataracts so easy to miss. They rarely arrive as a dramatic loss of sight. They arrive as a headlight that seems too bright, a menu that needs one more lamp, a sunset that looks a little less orange than it used to. The lens inside the eye clouds in three characteristic places, and each place changes the world in its own particular way.

Knowing which pattern you are living with will not diagnose you. It will, however, help you describe what you see, ask sharper questions at your eye exam, and understand why two friends with the same word on their charts can have very different days.

What are the 3 types of cataract, in plain terms?

The lens of the eye sits just behind the pupil, roughly the size and shape of a lentil. It is built in layers, like an onion: a dense central nucleus, a softer outer cortex, and a thin capsule wrapping the whole thing. A cataract is simply a cloudy region somewhere in that structure, and eye specialists name the three common age-related types by where the cloud forms.

Mayo Clinic groups them this way: nuclear cataracts affect the center, cortical cataracts affect the edges, and posterior subcapsular cataracts affect the back of the lens just inside the capsule. A fourth category, congenital cataract, is present at birth or develops in childhood and behaves differently enough that it deserves its own discussion later.

Type	Where it forms	What people notice first	Typical pace
Nuclear	Center of the lens	Yellowing of colors, dimmer distance vision, sometimes a brief improvement in near vision	Slow, over years
Cortical	Outer rim, spreading inward	Glare, halos, streaks around headlights	Variable
Posterior subcapsular	Back surface, inside the capsule	Trouble reading, bright-light glare, halos at night	Often faster than the other two

The location matters because light travels through the lens in a predictable path. A cloud in the middle dims everything evenly. A cloud at the rim only bothers you when the pupil widens, as it does at dusk. A cloud at the back sits almost exactly where light converges, so even a small one throws a large shadow on what you are trying to read.

Nuclear cataract: why the world slowly turns yellow

The nucleus is the oldest part of the lens. Its cells were laid down before you were born, and they never get replaced. Over decades, the proteins inside them clump and pigment, and the center of the lens hardens and yellows. Mayo Clinic describes the result: the lens may gradually turn more densely yellow, then brown, and the ability to distinguish shades of color fades.

Because the change is so gradual, people adapt without realizing it. Blues and purples become hard to tell apart. Whites go warm. Dim rooms feel dimmer than they should. Distance vision blurs first, and many people book an eye exam convinced they simply need stronger glasses.

There is a curious wrinkle. As the nucleus hardens, it bends light more strongly, which can temporarily improve close-up vision. Mayo Clinic notes that a nuclear cataract may at first cause more nearsightedness or even a short-lived improvement in reading vision, an effect long nicknamed “second sight.” Someone who has needed reading glasses for years suddenly finds they can read the newspaper without them and feels a decade younger. The improvement does not last, and it is a signal worth mentioning at your next appointment rather than a gift to enjoy quietly.

Nuclear cataracts are the classic slow-burn type. Many people live comfortably with a mild one for years, updating their glasses and adding brighter bulbs, until the dimming or color loss finally interferes with something they care about.

Cortical cataract: spokes, glare and halos

Picture a bicycle wheel viewed from the front. Now imagine a few of the spokes turning frosty white, starting at the rim and creeping toward the hub. That is roughly what an eye specialist sees when they look at a cortical cataract: wedge-shaped, whitish opacities forming in the outer cortex of the lens and extending inward.

The vision problems follow directly from that geometry. In bright daylight, the pupil constricts and light passes through the still-clear center, so vision may feel almost normal. At dusk or in a dark theater, the pupil widens, light hits the cloudy spokes, and it scatters. The everyday result is glare. Oncoming headlights bloom into starbursts. Streetlights grow halos. A lamp in the corner of a room seems to smear across the field of view.

Mayo Clinic lists this scattering as the hallmark of cortical cataracts: as the streaks slowly extend toward the center, they interfere with light passing through the lens. People with this type often say their vision is fine, then admit they have stopped driving after dark or that reading in sunlight has become uncomfortable in a way it never was before.

Cortical changes are common alongside nuclear ones, and they progress at a less predictable rate. Some stay at the rim for years. Others advance toward the center over a shorter period, and glare that was occasional becomes constant. Because the symptom is so tied to lighting, keeping a rough note of when vision is worst, night driving, low sun, indoor spotlights, gives your examiner genuinely useful information.

Posterior subcapsular cataract: the one that ruins reading and night driving

Of the three, this is the type people tend to notice fastest and resent most. It forms as a small, often granular patch on the back surface of the lens, tucked just inside the capsule. Its position is unlucky. Light entering the eye converges toward the back of the lens on its way to the retina, so a tiny opacity there blocks a disproportionate share of the light actually reaching the point of sharpest vision.

Mayo Clinic describes the typical experience: a posterior subcapsular cataract interferes with reading vision, reduces vision in bright light, and causes glare or halos around lights at night. The pattern is distinctive. Bright sunshine, which helps many people with other cataract types, makes things worse here, because the pupil constricts and funnels light straight through the cloudy patch. Dim rooms can paradoxically feel easier.

Reading suffers early. Small print near the eye is exactly the task that depends on light converging cleanly through the back of the lens, so a person may go from reading comfortably to struggling with a phone screen over a matter of months rather than years. Mayo Clinic notes that this type tends to progress faster than the other two.

It is also the type most often linked to factors beyond simple aging. Diabetes, long-term use of steroid medicines, previous eye inflammation, and eye injury all raise the risk, and posterior subcapsular changes can appear in people who are decades younger than the typical nuclear cataract patient. If you are in your forties or fifties and reading has suddenly become hard in bright light, it is worth saying so plainly at an eye exam rather than assuming presbyopia alone.

Which type of cataract is the most serious?

There is no official ranking, and any honest answer has to separate two ideas: which type disrupts daily life fastest, and which situation is medically most urgent.

On the first question, posterior subcapsular cataracts usually win the unwelcome prize. They progress more quickly than nuclear or cortical types, and they hit reading and night driving, the two tasks people most depend on for independence. Someone with a small posterior subcapsular cataract may be more disabled than someone with a much larger nuclear one.

On the second, the most serious cataract is generally not one of the three age-related types at all. Congenital cataracts in infants are treated as urgent because a developing visual system needs a clear image to wire itself correctly; a cloudy lens during those early months can leave lasting weakness in that eye even after the cataract is removed. The National Eye Institute notes that children can be born with cataracts or develop them early, and that these need prompt specialist attention.

A third category worries surgeons for practical reasons. A cataract left for very many years can become extremely dense and hard, sometimes described as brunescent or mature. Cleveland Clinic points out that cataracts eventually reach a stage where they severely impair vision, and very advanced lenses are technically harder to remove and carry higher surgical risk than earlier ones. This is why the modern approach is not to wait for a cataract to “ripen,” a piece of folk wisdom that belongs to an era before small-incision surgery.

So the fair answer: posterior subcapsular for speed, congenital for urgency, and neglected mature cataracts for surgical complexity. None of the three common types is dangerous to the eye in itself; the risk lies in what a person loses while living with poor vision, from falls to isolation.

Can you have more than one type at once?

Yes, and in older adults it is closer to the rule than the exception. The processes that cloud the nucleus and the cortex are both driven by aging lens proteins, so a person in their seventies commonly has a yellowing center and a few cortical spokes in the same eye. Add a small posterior subcapsular patch and all three are present at once, each contributing its own signature to what the person sees.

This is why symptoms so often refuse to fit a tidy description. A patient may report that colors look muted (nuclear), that headlights are unbearable (cortical), and that reading in the garden is impossible (posterior subcapsular). None of those complaints contradicts another. They are three clouds in three places.

The two eyes rarely match, either. Cataracts usually develop in both eyes but at different rates, and Mayo Clinic notes that the difference can itself be a problem: the clearer eye compensates so effectively that a person may not notice how poor the other has become until it is covered. This is one reason a routine eye exam catches cataracts that the patient never suspected.

Mixed cataracts do not change the treatment approach. Surgery removes the whole clouded lens regardless of which layers are affected, so a person with all three types is not facing three operations. What the mix does change is the conversation about timing. A modest nuclear cataract might be watched for years; the same eye with a growing posterior subcapsular component may reach the point of interfering with life much sooner, and the decision to operate rests on function, not on which label appears on the chart.

What causes each type, and what raises the risk?

The single biggest cause is time. The lens has no blood supply and cannot shed its old cells, so damage accumulates. Proteins that were once arranged in a precise, transparent lattice begin to unfold and clump, and the clumps scatter light. Mayo Clinic frames it simply: most cataracts develop when aging or injury changes the tissue that makes up the lens.

Beyond age, the risk factors listed by Mayo Clinic include diabetes, excessive exposure to sunlight, smoking, obesity, high blood pressure, previous eye injury or inflammation, previous eye surgery, prolonged use of steroid medicines, and heavy alcohol use. Some of these lean toward particular types. Ultraviolet exposure and smoking are associated more with nuclear and cortical changes. Diabetes and steroid medicines are especially linked with posterior subcapsular cataracts, and eye trauma can produce a cataract of almost any pattern, sometimes within months of the injury.

The scale is large. The National Eye Institute reports that by age 80, more than half of all Americans either have a cataract or have had cataract surgery. Globally, the World Health Organization identifies cataract as the leading cause of blindness, responsible for distance vision impairment in roughly 94 million people, largely because surgery remains out of reach in many parts of the world.

Genetics play a role that is real but not yet actionable. Cataracts run in some families, and certain inherited conditions cause them early. For most people, though, the modifiable list is short and familiar: protect the eyes from ultraviolet light, do not smoke, manage blood sugar and blood pressure well, and keep alcohol moderate. None of these prevents cataract outright. Each nudges the odds and, just as importantly, protects the retina and the rest of the eye that surgery cannot restore.

How is a cataract graded, and does the stage matter?

When an eye specialist dilates the pupil and looks through a slit lamp, they are not just deciding whether a cataract exists. They are noting its type, its location, and roughly how dense it is, often using a standardized grading scale that compares what they see against reference photographs. The words that end up in a chart, mild, moderate, dense, mature, describe that density.

The stages are less rigid than they sound. An early or immature cataract still lets a good deal of light through, and vision may be only slightly affected. A mature cataract has clouded the whole lens, and the pupil may look gray or white to the naked eye. A hypermature cataract has gone further still; the lens material has begun to break down, which can complicate surgery and, rarely, cause inflammation or pressure problems inside the eye.

Here is the part worth holding onto: the grade on the chart does not decide when to act. Cleveland Clinic and the National Eye Institute both make the same point in different words. Surgery is recommended when the cataract interferes with daily activities, not when it reaches a particular density. A moderate cataract that stops a bus driver from working matters more than a denser one in someone who is content with their vision.

Grading is still useful. It tells the surgeon how hard the lens will be to break up and remove, which influences technique and the length of the operation. It gives a baseline for tracking progression across yearly exams. And it explains why a friend with a “worse” cataract on paper may be advised to wait while you are advised to proceed. The number is a description of the lens. The decision is about the person.

What does vision actually look like with a cataract? Everyday comparisons

Descriptions in textbooks tend toward words like blurred and cloudy, which are accurate and almost useless. Patients describe it better.

A nuclear cataract is like looking through a photograph that has been left in the sun for years. Everything is still there, but the contrast has drained away and the whole scene has taken on a sepia cast. Whites look ivory. Navy and black become guesses. Reading a menu in a restaurant requires tilting it toward the candle.

A cortical cataract is like driving with a dirty windshield at night. In daylight the smears are invisible. Once headlights hit them, each one flares into streaks and rays, and the road itself seems to disappear behind the glare. People often describe seeing two or three overlapping images of a distant light, or a bright ring around the moon that no one else can see.

A posterior subcapsular cataract is like a thumbprint dead center on your reading glasses. Distance vision may be tolerable, but the page in front of you has a soft, gray hole where the words should be, and stepping outside into sunshine makes it worse rather than better. Screens become tiring within minutes.

Mayo Clinic’s symptom list captures the common threads across all three: clouded or dim vision, trouble seeing at night, sensitivity to light and glare, halos around lights, fading or yellowing of colors, double vision in one eye, and a need for frequent changes in glasses prescription. The last one is a quiet giveaway. When new glasses help for a few months and then stop helping, the problem is usually not the glasses.

One myth deserves retiring here: a cataract is not a film that grows over the eye. Nothing is on the surface. The clouding is inside the lens, which is why no drop, wipe, or rinse can clear it.

When is it time to consider cataract surgery?

The honest answer is when the cataract is costing you something you value. That sounds vague until you make the list concrete. Have you stopped driving at night? Do you avoid reading because it tires you? Have you missed a step, a curb, or a face across a room? Has a hobby that depends on fine detail, sewing, fishing, woodwork, quietly fallen away?

The National Eye Institute puts it directly: surgery is the only way to remove a cataract, and it is worth considering when the cataract keeps you from doing everyday activities. Cleveland Clinic offers the same guidance. There is no medical requirement to operate on a cataract that is not bothering you, and there is no advantage to waiting once it is. The old advice to let a cataract ripen before removal came from an era when surgeons needed a firm, whole lens to extract in one piece. Modern surgery breaks the lens up inside the eye, and a softer, earlier cataract is generally easier to remove than a rock-hard mature one.

There are also reasons a specialist may suggest surgery even when vision feels acceptable. If a cataract is dense enough to block the view of the retina, it can prevent monitoring of other conditions such as diabetic eye disease or macular degeneration. In some eyes, a thickening lens contributes to raised pressure. These are conversations for the examining clinician, not rules of thumb.

Timing between eyes is a common question. The NHS notes that when both eyes need surgery, they are usually treated one at a time, with a gap of several weeks, so that the first eye can settle and the second lens choice can be refined based on how the first turned out.

What lens do most people choose for cataract surgery, and how long does it last?

Cataract surgery does not just remove the cloudy lens. It replaces it with a clear artificial one, an intraocular lens, and the choice of lens is often the most consequential decision a patient makes.

The most commonly implanted type is a monofocal lens, which is set to a single focusing distance. Most people who choose monofocal lenses have them set for clear distance vision and then wear reading glasses for close work, an arrangement the National Eye Institute and Mayo Clinic both describe as the standard option. Some people instead choose monovision, with one eye set for distance and the other for near, which can reduce dependence on glasses but takes adjustment.

Other designs exist. Multifocal and extended-depth-of-focus lenses aim to provide clear vision at more than one distance; toric lenses correct astigmatism. Mayo Clinic notes that these premium options may reduce the need for glasses but can come with trade-offs such as halos or reduced contrast, and they are not suitable for every eye. A surgeon weighs the health of the retina, the shape of the cornea, and what the person actually does all day before recommending one.

On durability, the answer is reassuring. Cleveland Clinic states plainly that the artificial lens is permanent and does not need to be replaced. It cannot develop a cataract, because it is not living tissue. Lens exchange is rare and reserved for specific complications rather than wear. What can cloud over time is the thin natural capsule left in place to hold the new lens, which is a separate, treatable issue covered below.

The best lens is not the most expensive one. It is the one matched to your eyes and your life, chosen in a conversation where you have described honestly how you spend your waking hours.

What is the safest type of cataract surgery?

Nearly all cataract operations in high-income countries use a technique called phacoemulsification. The surgeon makes a tiny incision at the edge of the cornea, uses an ultrasound probe to break the clouded lens into fragments, suctions them out, and slides a folded artificial lens through the same opening, where it unfolds into place. The NHS describes the operation as usually taking 30 to 45 minutes, performed under local anesthetic with the patient awake, and most people go home the same day.

A variant uses a femtosecond laser to perform some of the initial steps, such as making the incisions and softening the lens, before the surgeon completes the procedure. Laser-assisted surgery is sometimes marketed as more precise, and the reasonable question is whether that translates into better or safer outcomes. The candid answer from the evidence is not yet. Large comparisons have not shown a consistent advantage in vision or complication rates over conventional phacoemulsification in experienced hands, and mainstream guidance treats both as safe standard options rather than one being superior.

What actually drives safety is less about the machine and more about the eye and the surgeon. Earlier, softer cataracts are easier to remove than dense mature ones. Eyes with other conditions, prior surgery, or very shallow anterior chambers carry more risk regardless of technique. Surgeon experience matters, as it does in any operation.

Complications are uncommon but real. The NHS lists them as including infection, bleeding, swelling of the retina, retinal detachment, and a rise in eye pressure, and notes that most can be treated. It also states that the risk of permanent sight loss from cataract surgery is very low. That last point is why cataract surgery is one of the most frequently performed operations worldwide: for most people, the balance of benefit and risk is unusually favorable.

What is a secondary cataract, and does it mean the cataract came back?

Months or years after successful surgery, some people notice their vision growing hazy again, with glare creeping back and colors dulling. The natural fear is that the cataract has returned. It has not; the removed lens cannot regrow. What has happened is that the thin capsule left in place to hold the artificial lens has become cloudy, a condition called posterior capsule opacification and commonly nicknamed a secondary cataract or after-cataract.

The mechanism is straightforward. A few lens cells inevitably remain on the capsule after surgery. Over time, some migrate across its back surface and lay down a hazy layer directly in the path of light, much like the original posterior subcapsular cataract in both location and effect. Reading blurs, night lights halo, and the improvement gained from surgery seems to slip away.

The NHS describes this as a common complication of cataract surgery and one of the most treatable. The fix is a brief outpatient laser procedure that opens a clear window in the cloudy capsule. It requires no incision, takes minutes, and vision typically clears within a day or two. Once the capsule is opened, the haze does not usually return.

This matters when people ask how long the results of cataract surgery last. The artificial lens itself is permanent. The capsule can cloud, and in some people it does. Distinguishing the two spares a great deal of worry. If your vision worsens after surgery, the sensible step is an eye exam to check whether the capsule is the culprit, or whether something unrelated, such as changes in the retina, is responsible. Both are worth knowing about, and neither means you have to go through the original operation again.

When should you see a doctor about cataract symptoms?

Cataracts themselves are slow, and a routine appointment is usually the right response to gradual dimming, glare, or color fading. Adults over 60 benefit from a dilated eye exam at least every one to two years, more often if they have diabetes or other eye disease, and the exam that finds a cataract also checks the retina and optic nerve behind it.

Some symptoms, however, do not belong to cataract and should not be waited on. Seek urgent care the same day if you experience a sudden loss or blurring of vision in one or both eyes, a curtain or shadow moving across part of your field of view, a sudden shower of new floaters or flashes of light, severe eye pain with a red eye and nausea, or a headache with vision loss. These can signal retinal detachment, acute glaucoma, or a stroke affecting the visual pathway, and each is time-sensitive in a way that cataract never is. Mayo Clinic advises making an appointment for any noticeable vision change and seeking immediate care for sudden changes, double vision, flashes, pain, or headache.

After cataract surgery, the NHS advises contacting the surgical team promptly if vision worsens rather than improves, if pain increases or is not relieved by simple measures, or if the eye becomes very red or sticky, since these can indicate infection or inflammation that needs quick attention.

Between those extremes sits a large gray area, and the guiding principle is simple. If a change in your vision is affecting how you live, whether that is reading, driving, working, or feeling steady on your feet, it is worth an appointment. Eye specialists would far rather see a cataract that is not yet ready for surgery than miss a treatable problem behind it.

What actually slows cataracts, and what is myth?

Cataracts attract remedies. Eye drops that claim to dissolve them, supplements that promise to reverse them, diets said to keep the lens crystal clear. It is worth being clear about what the evidence supports, because the honest list is shorter and less exciting than the marketing.

No drop, pill, or exercise has been shown to reverse a cataract or reliably stop one from progressing. The National Eye Institute is unambiguous that surgery is the only treatment that removes a cataract. Claims for products that clear the lens without surgery are not supported by mainstream evidence.

Prevention and slowing are a different matter, and here the advice is modest but real. Mayo Clinic recommends regular eye exams, not smoking, managing other health problems such as diabetes, wearing sunglasses that block ultraviolet light, limiting alcohol, and eating a diet rich in fruits and vegetables. The reasoning is mechanistic rather than miraculous. Ultraviolet light and cigarette smoke both drive oxidative damage to lens proteins; high blood sugar alters the lens chemistry in ways that favor clouding, especially at the back of the lens. Reducing those insults does not guarantee anything, but it removes accelerants.

Large trials of antioxidant supplements have not shown that they prevent cataract in well-nourished populations, which is why the emphasis falls on whole foods rather than capsules. Good hydration, screen breaks, and eye exercises are sensible for comfort and have no demonstrated effect on the lens.

One perspective is worth keeping. Because cataract is so treatable, the most valuable thing a person can do is protect the parts of the eye that are not: the retina, the optic nerve, the blood vessels that feed them. The same habits that modestly slow cataract, avoiding smoke, controlling blood sugar and pressure, shielding the eyes from the sun, are the ones that guard sight after the cataract itself is long gone.

Frequently asked questions

What are the 3 types of cataract?

The three common age-related types are nuclear, cortical, and posterior subcapsular, named for where in the lens the clouding forms. Nuclear cataracts cloud the central core and yellow vision gradually. Cortical cataracts form wedge-shaped streaks at the outer rim and cause glare. Posterior subcapsular cataracts appear at the back of the lens, affecting reading and bright-light vision. Many people develop a combination in the same eye.

What is the most serious cataract?

No single type is officially the most serious, but posterior subcapsular cataracts typically progress fastest and disrupt reading and night driving earliest. Congenital cataracts in infants are considered the most urgent because a clouded lens during early development can permanently weaken vision. Very dense, long-neglected mature cataracts are the most technically difficult to remove and carry more surgical risk than earlier ones.

How many years does a cataract lens last?

The artificial lens implanted during cataract surgery is designed to last a lifetime and does not need replacement. It is made of inert material that cannot cloud or develop a cataract. What can become hazy over time is the thin natural capsule that holds the lens in place, a condition called posterior capsule opacification, which is treated with a brief laser procedure rather than a new lens.

What lens do most people choose for cataract surgery?

Most people receive a monofocal lens set for clear distance vision, then use reading glasses for close work. Monofocal lenses are the standard option and are widely used because they give sharp, high-contrast vision at one distance with few side effects. Multifocal, extended-depth-of-focus, and toric lenses are alternatives that can reduce dependence on glasses but may cause halos or are unsuitable for some eyes.

What is the safest type of cataract surgery?

Phacoemulsification, which uses ultrasound to break up and remove the lens through a tiny incision, is the standard technique and has a strong safety record. Laser-assisted surgery performs some steps with a femtosecond laser, but comparisons have not shown it to be consistently safer or to give better vision. The surgeon’s experience and the condition of the eye influence safety more than the choice of technology.

Can you have more than one type of cataract in the same eye?

Yes, and mixed cataracts are common in older adults. The same aging processes affect the nucleus and cortex, so a yellowing center and cortical spokes often occur together, sometimes with a posterior subcapsular patch as well. This is why symptoms can seem contradictory, such as dulled colors, headlight glare, and trouble reading in sunlight all at once. Surgery removes the whole lens, so a mix does not require multiple operations.

Do cataracts always get worse?

Cataracts generally progress over time, though the pace varies widely by type and person. Nuclear cataracts often change slowly over many years, while posterior subcapsular cataracts tend to advance faster. No treatment reverses a cataract, but many people live comfortably with a mild one for years using updated glasses and better lighting. Surgery is recommended when the cataract begins to interfere with daily activities.

Why do colors look yellow or faded with a cataract?

A nuclear cataract causes the central lens to accumulate pigment, gradually turning it yellow and then brown. Light passing through this tinted lens loses its blue and violet wavelengths, so whites look cream, blues look gray, and colors lose their vividness. Because the shift is gradual, the brain adapts and people rarely notice until after surgery, when colors often appear startlingly bright by comparison.

What is a secondary cataract after surgery?

A secondary cataract, or posterior capsule opacification, is clouding of the thin natural capsule left in place to support the artificial lens. Residual lens cells spread across the capsule and create haze that blurs vision and causes glare, mimicking the original cataract. It is a common and very treatable complication: a brief outpatient laser procedure opens a clear window in the capsule, and vision usually improves within days.

Can you prevent cataracts with diet or supplements?

No diet or supplement has been proven to prevent or reverse cataracts. Mainstream guidance supports habits that may slow their development and protect overall eye health: not smoking, wearing sunglasses that block ultraviolet light, managing diabetes and blood pressure, limiting alcohol, and eating plenty of fruits and vegetables. Antioxidant supplements have not shown clear benefit in large trials, so the emphasis is on whole foods rather than capsules.

References

• National Eye Institute (NIH): Cataracts
• NHS: Age-related cataracts
• NHS: Cataract surgery
• Cleveland Clinic: Cataracts

This article is for general information only and is not a substitute for professional medical advice. Please consult a qualified doctor about your individual situation.