When an infection isn’t treated promptly, it can spiral into something far more dangerous. 

Sepsis is a life-threatening condition in which the body’s response to infection begins to damage its own tissues and organs. Knowing when to act could save your life or the life of someone you love.

Bonnie Vrbicky, PA-C, an emergency medicine physician assistant, explains what sepsis is, who’s most at risk and when to seek emergency care.

What is sepsis?

Sepsis occurs when the body’s immune response to an infection goes into overdrive. 

“The definition of sepsis is a life-threatening organ dysfunction caused by your body’s response to an infection,” Vrbicky says. “Most of the time, it’s an untreated infection.”

That’s an important distinction. Sepsis doesn’t typically appear out of nowhere. It develops when an infection – in the lungs, urinary tract, skin, abdomen or elsewhere – isn’t treated and gets worse.

Any infection can lead to sepsis. That includes:

• Pneumonia.
• Urinary tract infections (UTIs).
• Meningitis (infection of the brain).
• Pericarditis (infection of the heart).
• Cellulitis (skin infection).
• Appendicitis.
• Infections of the gallbladder or intestines.

Many types of bacteria can cause these infections. For example, strep and staph are common culprits in skin infections. E. coli is the most frequent cause of UTIs. Pneumonia has many bacterial triggers, though there is a vaccine that covers the most common strain.

What are the warning signs of sepsis?

Recognizing sepsis at home can be difficult because many of the diagnostic criteria, like lab values and vital signs, require medical equipment. That said, certain symptoms should prompt you to seek care right away.

Watch for:

• Fever, especially one that persists for more than a couple of days.
• Rapid heart rate or rapid breathing.
• Feeling like you were getting better, then suddenly getting worse.
• Chest pain or shortness of breath.
• Severe abdominal pain.
• Vomiting and severe pain, particularly with a suspected kidney or bladder infection.

A pattern of improving and then worsening is a red flag, according to Vrbicky.

“You should continue to get better,” she says. “If you get worse initially, then get better, and then get worse again – that’s odd.”

How is sepsis different from the flu or a stomach bug?

It can be hard to tell – even for clinicians. 

“Sometimes in the ER, I don’t know initially whether it is true sepsis,” Vrbicky says. “If you present with a fever, a fast heart rate and you’re breathing fast, those symptoms can go along with sepsis, influenza or a stomach bug.”

That’s why emergency providers often begin treatment while they’re still running tests. Fluids and antibiotics are the cornerstones of early sepsis treatment and starting them quickly makes a real difference in outcomes.

What is septic shock, and how does it differ from sepsis?

Think of sepsis and septic shock as points on a spectrum. 

“A person can show up in sepsis, but in general, their body is handling it,” Vrbicky says. “Septic shock is when the body starts to not handle it well.”

With septic shock, blood pressure can drop to dangerous levels. Some patients need ICU-level care, medications to raise blood pressure or central IV access rather than a standard peripheral line.

Who is most at risk?

While sepsis can happen to anyone, some people face a higher risk:

• Adults 65 and older.
• Young children, particularly those under two years old.
• People with chronic conditions such as diabetes, asthma or autoimmune disorders.
• Cancer patients or others who are immunocompromised.

“Those who are immunocompromised, or the really young and really old, may seem fine one minute and the next hour, they are not doing well,” Vrbicky says.

Children are particularly unpredictable. 

“Kiddos tend to put on a strong face until suddenly their bodies can’t do it anymore, and then they crumple really fast,” she says.

Even healthy adults aren’t immune. A common UTI, for example, can become serious when symptoms are masked by over-the-counter remedies that relieve discomfort without clearing the infection. 

“You can ignore it, or you can even take meds to make the symptoms go away, but not the infection,” Vrbicky says.

How is sepsis diagnosed and treated?

In the emergency department, providers look at a combination of factors, including: 

• White blood cell count.
• Heart rate.
• Breathing rate.
• Fever.
• A blood test called the lactic acid level, which is often elevated in sepsis. 

Blood cultures, which are small samples grown in a lab, can help identify the specific bacteria causing the infection.

Treatment typically involves IV fluids to support blood pressure and combat dehydration, along with antibiotics. Because clinicians often don’t know the exact bacterial source right away, they start with broad-spectrum antibiotics that cover a wide range of organisms. Once lab results identify the specific bacteria, treatment can be refined to a more targeted antibiotic. Imaging tests, such as chest X-rays may also help identify the source of infection.

When should you go to the emergency room?

Seek emergency care if you or someone you care for experiences any of the following:

• A fever lasting more than two days.
• Worsening illness after feeling better.
• Chest pain or shortness of breath.
• Severe abdominal pain.
• Confusion.
• Weakness.

“Surviving sepsis is about getting early treatment,” Vrbicky says. “If you’re having these symptoms, you’ll want to be checked out more emergently than wait until you can get into your primary care.”