Sepsis: What Are the Warning Signs of an Infection Gone Wrong?

Sepsis warning signs are the body-wide symptoms that can appear when an infection, often one that started as something ordinary, sets off an extreme reaction that can injure organs. Common signs include confusion, fast breathing, a racing heart, fever or shaking chills, and feeling far sicker than the infection would explain. Sepsis is a medical emergency that can progress quickly. This article explains the signs, who is at higher risk, what hospitals do, and which symptoms call for 911.

Sepsis warning signs: what to look for in an infection

According to MedlinePlus (NIH), sepsis is the body's extreme response to an infection. Your immune system normally fights germs in one area, such as the lungs, bladder or skin. In sepsis, the response spreads through the body and can damage tissues and organs. The exact reasons some infections lead to sepsis are not fully understood, and several factors, including the germ, the site of infection and your own health, probably contribute.

Sepsis is not a separate illness that you "catch." It is a complication of an infection you already have. That is why the most useful question is not "do I have sepsis?" but "is my infection behaving differently than it should?"

Signs that may suggest sepsis include:

• Confusion or unusual sleepiness. A person may seem disoriented, speak oddly, or be hard to wake.
• Fast breathing or shortness of breath. Breathing may look labored even at rest.
• A racing heartbeat. Your pulse may feel pounding or very fast while you are lying still.
• Fever, shivering or feeling very cold. Some people, especially older adults, have a low temperature instead of a high one.
• Clammy, sweaty or mottled skin. Skin may look pale, gray, blotchy or bluish.
• Extreme pain or discomfort. Many people describe feeling like this is the worst they have ever felt.
• Little or no urination. This can be a sign that the kidneys are not getting enough blood flow.
• Lightheadedness or fainting when standing, which can reflect low blood pressure.

One symptom on this list does not establish sepsis. Many of them occur with a bad flu or a stomach virus. What raises concern is a combination, a fast change, or a sense that something is seriously wrong.

Why a "normal" infection can turn serious

Sepsis can begin from many sources. Common starting points include pneumonia, urinary tract infections, infected skin or wounds, and infections in the abdomen. Bacteria are a frequent cause, but viruses can also lead to sepsis, as described in a review of the immune pathogenesis of viral sepsis on PubMed Central. Fungi can be involved too, particularly in people with weakened immune systems.

If you are comparing symptoms, our pages on bronchitis versus pneumonia and on how to tell if a cut is getting infected cover those starting points. The rest of this article focuses on what happens when an infection spreads beyond its original site.

When the body's response becomes extreme, blood flow to organs can drop. MedlinePlus notes that severe sepsis can lead to septic shock, in which blood pressure falls to a dangerous level and organs may stop working properly. Outcomes vary a great deal depending on how early treatment starts, the person's underlying health, and the type of infection.

Who is more likely to develop sepsis

Anyone with an infection can develop sepsis, including healthy young adults. Some groups are at higher risk, and for them a lower threshold for seeking care makes sense:

• Adults 65 and older
• Infants and very young children
• People with chronic conditions such as diabetes, kidney disease, lung disease or cancer
• People with weakened immune systems, including those taking chemotherapy or medicines that suppress immunity
• People who recently had surgery, a hospital stay, or a medical device such as a urinary catheter or IV line
• People with severe burns or large wounds

Older adults and people with weakened immune systems may not mount a typical fever, and infection can show up as new confusion, unusual weakness, a general decline or a low temperature. Tell your clinician about any such change, even when your temperature seems normal.

During chemotherapy, a fever of 100.4°F (38°C) or higher, or shaking chills, needs emergency care. Chemotherapy can lower the white blood cells that fight infection, so a minor infection may become serious quickly. Call your oncology team or go to the ER right away, and do not wait to see whether it passes.

After surgery, a hospital stay, or with a catheter or IV line, a fever or shaking chills that is getting worse is a higher-risk situation. Get evaluated the same day, and go to the ER if you also feel very unwell, have a fast heartbeat or fast breathing, or are confused.

Sepsis signs in infants and young children

Babies and children cannot describe how they feel, so parents look at behavior. Concerning changes can include unusual drowsiness or difficulty waking, a limp or floppy body, refusing to feed, fast or labored breathing, a cold or mottled look to the hands and feet, and a cry that sounds weak or high-pitched. A child who has a fever but is playful and drinking is usually less worrying than a child who has a fever and seems "not themselves."

Young babies are a special case. A fever of 100.4°F (38°C) or higher in a baby under 3 months, or an unusually low temperature, needs emergency evaluation right away, even if the baby looks well. Very young infants can have serious infections with few obvious signs.

Some bacterial infections that cause sepsis can also cause meningitis or a rash. MedlinePlus lists a rash of small purple or dark red spots among the signs of meningococcal disease, a serious bacterial infection that can lead to sepsis. That rash can be a reason to call 911 immediately. Our pages on ear infections and urinary tract infections in young children cover those common illnesses; this page is about the less common situation in which a child's illness is escalating.

For fever medicine in children, follow the product label and ask your pediatrician or pharmacist about the right product and amount for your child's age and weight. Do not rely on a fever reducer to judge whether a child is seriously ill, because a child can still look very unwell after the temperature comes down.

How clinicians decide whether it is sepsis

There is no single test that confirms or rules out sepsis. Clinicians combine your history, an examination, and testing. They usually check temperature, heart rate, breathing rate, blood pressure, and oxygen levels, and they look at mental status. Blood tests can include cultures to look for germs in the blood, a lactate level, and measures of kidney and liver function and blood counts. They may also order urine tests, chest imaging, or scans to look for the source of infection.

Because sepsis can progress quickly, treatment often begins before every result is back. A clinician who strongly suspects sepsis may start treatment while the workup continues.

What treatment in the hospital looks like

MedlinePlus describes sepsis as needing treatment in a hospital, often in an intensive care unit. Care typically includes:

• Antimicrobial medicine. Antibiotics are given intravenously when a bacterial infection is suspected. Antifungal or antiviral medicine may be used when those germs are involved.
• IV fluids to support blood pressure and organ perfusion.
• Oxygen or breathing support when the lungs are affected.
• Medicines to raise blood pressure if it stays low despite fluids.
• Treating the source. This may include draining an abscess, removing an infected device, or surgery to remove infected tissue.

Never start, stop or change a prescribed antibiotic on your own. If you are already taking one and are getting worse, that is a reason to be evaluated promptly, not to wait for the course to finish. Ask your prescriber or pharmacist about the label cautions for any antibiotic you take, since side effects and interactions differ between drugs.

Infections that can lead to sepsis and need prompt attention

Several specific infections can progress to sepsis. Pneumonia can cause it, and Legionnaires' disease, a serious lung infection caused by Legionella bacteria, is one example described by MedlinePlus. Meningococcal disease can cause meningitis and bloodstream infection. Endocarditis, an infection of the heart's inner lining or valves, can seed bacteria into the blood. Urinary tract infections that reach the kidneys, and abdominal infections such as a ruptured appendix or infected gallbladder, can also spread.

You do not need to memorize these. The practical point is that an infection with high fever, back or flank pain, severe abdominal pain, a stiff neck, or breathing trouble deserves prompt evaluation rather than waiting to see if it passes.

Skin infections that spread fast

Most skin infections are mild, with redness, warmth or a small amount of pus that spreads slowly. These deserve same-day evaluation, particularly if you have diabetes or a weakened immune system. A small number of skin and soft-tissue infections are different. A deep infection such as necrotizing fasciitis can spread quickly and may lead to septic shock. Warning features include redness that is spreading fast or red streaks moving up a limb, pain that seems much worse than the skin looks, blisters, skin that turns dusky, dark or black, a crackling feel under the skin, or fever and feeling very unwell. These features need emergency care: call 911 or go to the ER immediately rather than waiting for an appointment.

Staying hydrated and watching trends at home

If you are caring for someone with an infection at home, watch the direction of change. Improving over a day or two is reassuring. Getting worse, or developing new symptoms such as confusion, fast breathing or very little urine, is a reason to seek care. Dehydration can look similar to early sepsis and can also occur alongside it; our page on signs of dehydration lists what to watch for. Because the two overlap, a person who is dizzy, very weak and passing little urine, or who cannot keep any fluids down, should be evaluated the same day rather than assumed to just need fluids. Go to the ER if they are also confused, faint, or have a racing heart.

Recovery and what can follow

Many people recover fully, but some have lingering problems after sepsis. These can include fatigue, trouble sleeping, difficulty concentrating, muscle weakness, anxiety, and low mood. Organ damage, such as to the kidneys, can sometimes persist. If you notice these problems after a serious infection, tell your clinician so they can look for causes and support. Low mood or thoughts of harming yourself deserve prompt attention: in the US, you can call or text 988 to reach the Suicide and Crisis Lifeline.

Lowering the chance of a serious infection

• Keep vaccinations current. Ask your clinician which vaccines fit your age and health conditions, since some prevent infections that can lead to sepsis.
• Clean cuts and scrapes with soap and water and watch them for spreading redness, warmth, swelling or pus.
• Manage chronic conditions such as diabetes with your care team.
• Wash your hands regularly.
• Tell a clinician early about infection symptoms if you are in a higher-risk group.

Prevention reduces risk but cannot remove it. If an infection feels wrong to you, it is reasonable to say so plainly when you call or arrive: "I am worried this could be sepsis." Clinicians generally take that concern seriously.

When to Seek Medical Care