Sepsis

What is sepsis?

Sepsis is a life-threatening medical emergency that happens when the body’s response to an infection spirals out of control and begins to damage its own tissues and organs. In a healthy response, the immune system fights an infection locally — for example, in the lungs, urinary tract, or skin. In sepsis, the chemicals the immune system releases into the bloodstream to fight the infection trigger widespread inflammation throughout the body. This inflammation can cause blood clots and leaky blood vessels, which reduce blood flow to vital organs such as the brain, heart, and kidneys. Without prompt treatment, sepsis can progress to septic shock — a severe drop in blood pressure that can lead to organ failure and death.

Many people ask, “what is sepsis, exactly — is it an infection?” It is helpful to understand that sepsis is not the infection itself. It is the body’s extreme, harmful reaction to an infection. Any infection — bacterial, viral, fungal, or parasitic — can potentially lead to sepsis, although bacterial infections are the most common trigger.

Sepsis can affect anyone, at any age. However, it occurs more often in very young children, older adults, people with weakened immune systems, and people with long-term (chronic) health conditions. Sepsis is recognized worldwide as a leading cause of death in hospitals, which is why early recognition of sepsis symptoms and rapid treatment matter so much. The medical code A41.9 refers to sepsis when the specific organism causing it has not been identified.

Symptoms of sepsis

Sepsis symptoms can develop quickly, sometimes over just a few hours, and they can be subtle at first — especially in older adults, infants, and people with weakened immune systems. Because sepsis starts with an infection, early signs often overlap with the symptoms of that infection, such as a cough, painful urination, or a wound that looks red and swollen.

Common warning signs of sepsis include:

• Fever, shivering, or feeling very cold — some people, especially older adults, may have a low body temperature (hypothermia) instead of a fever.
• Rapid heart rate — the heart beats faster to try to keep blood flowing to the organs.
• Rapid, shallow breathing or shortness of breath.
• Confusion, disorientation, or unusual sleepiness — changes in mental state are an important and often overlooked sign, particularly in the elderly.
• Extreme pain or discomfort — many survivors describe feeling “the worst I have ever felt.”
• Clammy, sweaty, pale, or mottled (blotchy) skin.
• Reduced urination — passing much less urine than normal can signal that the kidneys are under strain.

Symptoms often differ by stage. In early sepsis, a person may simply seem unusually unwell with an infection — feverish, fast-breathing, and tired. As sepsis progresses to what doctors call severe sepsis, signs of organ trouble appear: marked confusion, difficulty breathing, abdominal pain, very low urine output, or abnormal heart function. In septic shock, the most dangerous stage, blood pressure drops so low that it does not respond adequately to intravenous (given through a vein) fluids alone. A person in septic shock may be cold and clammy, barely responsive, and critically ill.

In babies and young children, sepsis may look different: poor feeding, unusual floppiness or irritability, a bulging soft spot on the head, very fast breathing, a rash that does not fade when pressed, or fewer wet diapers than usual. Any of these signs in a child with a suspected infection needs urgent medical assessment.

Causes and risk factors

Sepsis causes always begin with an infection somewhere in the body. The infections most often linked to sepsis include:

• Lung infections, such as pneumonia (infection of the air sacs in the lungs).
• Urinary tract infections, including kidney infections.
• Abdominal infections, such as appendicitis, a perforated bowel, or infections of the gallbladder or liver.
• Skin and soft-tissue infections, including infected wounds, surgical sites, pressure sores, and cellulitis (a spreading skin infection).
• Bloodstream infections, sometimes related to intravenous lines or catheters (thin tubes placed into the body for treatment).

Bacteria are the most frequent cause, but viruses (including influenza and COVID-19), fungi, and parasites can also trigger sepsis. In many cases, doctors cannot identify the exact organism responsible, which does not change the urgency of treatment.

While anyone can develop sepsis, certain groups face a higher risk:

• Adults over 65 and infants under one year, whose immune systems are weaker or still developing.
• People with weakened immune systems, for example due to cancer treatment, organ transplantation, HIV, or long-term steroid use.
• People with chronic illnesses such as diabetes, kidney disease, liver disease, or lung disease.
• People who were recently hospitalized, had surgery, or spent time in an intensive care unit.
• People with invasive devices such as urinary catheters, breathing tubes, or intravenous lines.
• Pregnant women and women who have recently given birth, who can develop maternal sepsis.
• People who have survived sepsis before, as a previous episode can increase the risk of another.

It is worth stressing that sepsis can also strike previously healthy people after an ordinary-seeming infection, such as a scraped knee or a bout of flu. This is why awareness of the warning signs is important for everyone, not only high-risk groups.

Diagnosis

There is no single test that confirms sepsis on its own. Instead, sepsis diagnosis relies on a combination of the doctor’s clinical assessment, laboratory tests, and — where needed — imaging studies to find the source of the infection. Because time is critical, doctors often begin treatment while test results are still pending.

A typical diagnostic workup may include:

• Physical examination and vital signs — doctors check temperature, heart rate, breathing rate, blood pressure, oxygen levels, and mental alertness. Scoring tools such as SOFA (Sequential Organ Failure Assessment) or the simpler qSOFA help clinicians judge how severely the organs are affected.
• Blood tests — these commonly include a complete blood count (looking at white blood cells, which fight infection), markers of inflammation such as C-reactive protein or procalcitonin, lactate (a substance that rises when tissues are not getting enough oxygen), and tests of kidney and liver function and blood clotting.
• Blood cultures — samples of blood are sent to the laboratory to see whether bacteria or fungi grow, which helps identify the organism and choose the most effective antibiotic. Cultures may also be taken from urine, sputum (mucus from the lungs), wound fluid, or spinal fluid, depending on the suspected source.
• Imaging — a chest X-ray may reveal pneumonia; ultrasound, CT (computed tomography) scanning, or MRI (magnetic resonance imaging) can locate infections in the abdomen, kidneys, or soft tissues.

Doctors generally suspect sepsis when a patient has a confirmed or likely infection together with signs that organs are beginning to malfunction — such as low blood pressure, confusion, rapid breathing, elevated lactate, or reduced urine output. Septic shock is diagnosed when blood pressure remains dangerously low despite adequate fluid replacement and the patient requires special medications to support circulation.

Because early sepsis can mimic other conditions — including severe flu, heart problems, or dehydration — repeated assessment is common. If you or a loved one is being evaluated for a serious infection, it is reasonable to ask the medical team directly: “Could this be sepsis?”

Treatment options for sepsis

Sepsis treatment is a medical emergency, and there is no role for watchful waiting once sepsis is suspected. Treatment usually takes place in a hospital, often in an intensive care unit (ICU), and the earlier it starts, the better the chances of recovery. In many hospital systems, sepsis is managed jointly by emergency, intensive care, and infectious disease specialists; at Acibadem, for example, the Infectious Diseases Department is among the units involved in diagnosing and treating serious infections that can lead to sepsis.

Medications

• Antibiotics — broad-spectrum antibiotics (medicines that work against many types of bacteria) are usually started intravenously as soon as possible, often within the first hour of recognizing sepsis. Once culture results identify the specific organism, doctors may switch to a more targeted antibiotic. If a virus or fungus is the cause, antiviral or antifungal medicines are used instead or in addition.
• Intravenous fluids — large volumes of fluid are given through a vein to restore blood pressure and improve blood flow to the organs.
• Vasopressors — if blood pressure remains too low after fluids, medications called vasopressors are used to tighten blood vessels and raise blood pressure. Their use is a defining feature of septic shock.
• Other supportive medications — depending on the situation, doctors may use corticosteroids (anti-inflammatory hormones), insulin to control blood sugar, or medicines to support heart function.

Supportive care

Because sepsis can affect multiple organs, supportive care is a central part of treatment. This may include supplemental oxygen or, in severe cases, mechanical ventilation (a machine that helps with breathing), dialysis if the kidneys fail temporarily, and careful monitoring of heart function, urine output, and blood chemistry. Nutrition support and prevention of blood clots and pressure sores are also part of routine ICU care.

Procedures and surgery

Treating sepsis often requires controlling the source of the infection, not just giving antibiotics. Depending on where the infection is, this may involve:

• Draining an abscess (a collection of pus), either through the skin using imaging guidance or surgically.
• Removing infected devices, such as an intravenous line or urinary catheter that is the source of infection.
• Surgery to remove infected or dead tissue — for example, operating on a perforated bowel, an infected gallbladder, or severely infected soft tissue.

Your medical team will decide which combination of these measures is appropriate based on the source of infection, the organism involved, and how the body is responding. Treatment plans are frequently adjusted as new test results arrive.

Living with sepsis and outlook

The outlook after sepsis varies widely. Many people who receive prompt treatment recover fully, especially when sepsis is caught early and the underlying infection responds well to antibiotics. Others — particularly older adults, people with chronic illnesses, and those who develop septic shock — face a longer and more difficult recovery, and sadly, some people do not survive despite the best available care. Doctors cannot promise a particular outcome; survival and recovery depend on how quickly treatment begins, the source and severity of the infection, and the person’s overall health.

Recovery does not always end when the infection clears. A significant number of survivors experience what is known as post-sepsis syndrome — a group of lingering physical and psychological effects that can last for weeks, months, or in some cases longer. These may include:

• Extreme fatigue and muscle weakness.
• Difficulty concentrating, memory problems, or “brain fog.”
• Sleep disturbances and nightmares.
• Anxiety, depression, or symptoms of post-traumatic stress.
• Joint and muscle pain, and reduced physical stamina.
• A higher risk of repeat infections and, in some people, another episode of sepsis.

Rehabilitation after sepsis is often gradual. Physical therapy can help rebuild strength, and follow-up appointments allow doctors to monitor organ function — for example, checking whether the kidneys have fully recovered. Survivors are usually encouraged to stay up to date with vaccinations, treat new infections promptly, care for wounds carefully, and seek medical advice early if they feel unwell, since a previous episode of sepsis can increase the risk of future ones. Emotional recovery matters too; many survivors and their families benefit from counseling or support groups as they process what was often a frightening, life-changing illness.

Frequently asked questions

What is sepsis in simple terms?

Sepsis is the body’s extreme, harmful overreaction to an infection. Instead of fighting the infection in one place, the immune system floods the whole body with inflammatory chemicals, which can damage organs and dangerously lower blood pressure. It is a medical emergency that requires hospital treatment, usually including intravenous antibiotics and fluids.

How serious is sepsis?

Sepsis is very serious and can be fatal, particularly if treatment is delayed or if it progresses to septic shock. That said, many people survive sepsis, especially when it is recognized early and treated promptly. Seriousness depends on factors such as the person’s age and overall health, the source of the infection, and how quickly organ problems are addressed.

Can sepsis be cured?

Sepsis can often be treated successfully with antibiotics, intravenous fluids, and supportive hospital care, and many people make a full recovery. However, there is no guarantee: outcomes vary from person to person, and some survivors experience lasting effects known as post-sepsis syndrome. The single most important factor within anyone’s control is seeking medical help quickly when warning signs appear.

What are the first signs of sepsis?

Early sepsis symptoms often include fever or feeling unusually cold, a fast heartbeat, rapid breathing, confusion or unusual drowsiness, severe pain or discomfort, and clammy or pale skin — usually in someone who already has, or recently had, an infection. In older adults, sudden confusion may be the most noticeable early sign. Because these signs can be subtle, any rapid worsening during an infection deserves urgent medical attention.

What usually causes sepsis?

The most common sepsis causes are bacterial infections of the lungs (pneumonia), urinary tract, abdomen, and skin or soft tissues. Viruses, fungi, and parasites can also trigger sepsis. Sometimes the exact organism is never identified, but this does not change how urgently sepsis needs to be treated.

How long does it take to recover from sepsis?

Recovery time varies widely. Some people feel back to normal within a few weeks, while others — especially those who needed intensive care — may take months to regain their strength. Fatigue, weakness, poor concentration, and mood changes are common during recovery and usually improve gradually. Your doctor may recommend follow-up visits, rehabilitation, or physical therapy depending on how severe the illness was.

Can sepsis come back after treatment?

Yes, it is possible. People who have had sepsis once are at increased risk of developing it again, because their immune system may be weakened for a period after the illness and because underlying risk factors often remain. Survivors are generally advised to treat new infections early, keep vaccinations up to date, and seek medical advice promptly if they develop signs of infection.

When to see a doctor

Sepsis progresses quickly, and every hour matters. If you or someone you care for has an infection — or recently had one — and develops any of the following red-flag signs, seek emergency medical care immediately:

• Confusion, slurred speech, or extreme drowsiness — being difficult to wake or not making sense.
• Very fast or difficult breathing, or breathlessness at rest.
• A rapid or pounding heartbeat combined with feeling very unwell.
• Fever with severe shivering, or an unusually low body temperature with cold, clammy skin.
• Mottled, bluish, or very pale skin, or a rash that does not fade when a glass is pressed against it.
• Little or no urination over many hours.
• Severe pain or a feeling of impending doom — feeling worse than ever before.
• In babies and children: unusual floppiness, refusal to feed, a weak or high-pitched cry, very fast breathing, or fewer wet diapers than normal.

Even if you are not sure whether it is sepsis, do not wait to see if symptoms improve on their own. Tell the medical team clearly that you are concerned about sepsis — asking the question directly can help prompt rapid assessment. For less urgent concerns, such as an infection that is not improving with treatment, contact your doctor promptly rather than delaying, since treating infections early is one of the most effective ways to prevent sepsis from developing.