Some people with lupus experience excessive sweating and frequent overheating, while others say their blood feels like it’s boiling. A full-body burning sensation is a common experience among MyLupusTeam members.

“I feel like I’m literally on fire sometimes,” one member said.

Another said, “I’m always hot. I’ll become really hot, and my body will feel hot, but everyone around me is fine.”

A third member put it this way: “I try to avoid getting hot. If I do, I feel like I am burning from the inside out!”

Feeling like your body is on fire or that your blood is boiling may be a sign that you’re running a fever or a high temperature. Fever is a common symptom of lupus. Research shows that 36 percent to 86 percent of people with systemic lupus erythematosus (SLE), the most common type of lupus, experience fevers.

A high temperature or fever can have many different causes for people with lupus. Knowing what’s causing you to feel hot or feverish is important. It may indicate an underlying condition that needs treatment or that your lupus management plan needs to be updated. Below are seven reasons why your blood feels like it’s boiling.

1. Lupus Flare

Feeling really hot or running a fever may mean a lupus flare is coming. Research has shown that the most common cause of fever in people with lupus is disease activity. For example, one study in the journal Cureus found that as much as 60 percent of fevers with lupus are caused by active SLE.

If you’re unsure if the heat running through your body is a sign of a flare, take note of any other symptoms or triggers you know usually precede a flare-up. You may notice that feeling extremely hot is part of the pattern. However, while it’s common for fever to be a sign of lupus activity, there may be a different underlying cause that requires a healthcare provider to diagnose.

2. Infection

When someone living with lupus has a fever, doctors typically first rule out infection. That’s because lupus and its treatments can weaken the immune system, making infections more likely. Most infections in people with lupus are bacterial and often affect the urinary tract, skin, or respiratory system.

A healthcare provider may order blood tests to look for biological markers that help show whether a fever is due to an infection or lupus disease activity. If the fever doesn’t go away after taking medications like acetaminophen or nonsteroidal anti-inflammatory drugs (NSAIDs), an infection may be the more likely cause. Fevers caused by lupus flares often respond to these medications and begin to improve.

Lupus itself is a risk factor for infection, as it can negatively affect the immune system and limit its ability to fight infection. Taking immunosuppressive medications may increase the risk of infections because they’re designed to limit the body’s overactive immune system. Therefore, people with lupus who have been taking glucocorticoids and immunosuppressive medications for a long time may have more frequent bouts of infection-induced fever.

It’s crucial to determine whether an infection is responsible for your elevated body temperature, as the treatment for the fever varies depending on the underlying cause. Make sure to talk to your healthcare provider if you’re concerned about infections, including getting any recommended vaccines.

3. Vasculitis

Vasculitis occurs when both large and small blood vessels are inflamed. Because lupus can cause inflammation in different parts of the body, including the blood vessels, people with lupus may be more likely to have vasculitis.

One of the general symptoms of vasculitis is fever. Other symptoms include:

• Fatigue (extreme tiredness that doesn’t improve with rest)
• Pain in the muscles or joints
• General discomfort or malaise
• Lack of appetite
• Unintentional weight loss

Vasculitis can cause many other symptoms in specific areas of the body, depending on where the inflammation is. For example, vasculitis may affect the intestines and lead to stomach pain, cramps, bloating, or blood in your stool (poop).

In addition to lupus, certain medications, health conditions, or infections may also cause vasculitis. Vasculitis can restrict blood flow to vital organs and tissues, so it’s important to talk to your healthcare provider if you’re concerned you may have it.

4. Illness

If you have a fever or low-grade fever, it may indicate that you’re coming down with an illness. Many illnesses cause fevers, and knowing exactly which one may be circulating in your body requires a healthcare provider’s diagnosis.

Some illnesses that commonly cause fever include:

• Flu
• Common cold
• Ear infection
• Bronchitis (inflammation of the airways)
• Group A streptococcus infection (strep throat)
• Infectious mononucleosis (mono)
• Urinary tract infection (UTI)

While rare, some illnesses that researchers have found to cause fevers in people with lupus include:

• Autoinflammatory disorders — For example, familial Mediterranean fever
• Sarcoidosis — When clusters of inflammatory cells form lumps called granulomas
• Rheumatic fever — Often an immune response to an infection

Research on the co-occurrence of lupus and the above illnesses is limited and generally considered rare.

5. Kidney Problems

Fever, along with other symptoms like muscle pain, swollen or painful joints, and a rash across the nose and cheeks (often called a butterfly rash) may indicate kidney problems in people with lupus.

It’s very common for people with lupus to have kidney problems — 5 out of 10 adults and 8 out of 10 children with lupus will develop kidney disease, also called lupus nephritis, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Lupus nephritis is more common in men than women, and “African Americans, Hispanics/Latinos, and Asian Americans are more likely to develop lupus nephritis than Caucasians,” according to the NIDDK.

Other symptoms of lupus nephritis include:

• Weight gain
• Frequent urination, especially at night
• Foamy urine
• Hematuria (blood in the urine)
• Hypertension (high blood pressure)

You may not notice symptoms of lupus nephritis at first, but it’s important to let your healthcare provider know if you experience any changes or symptoms. Left untreated, lupus-related kidney problems can get worse over time and may lead to kidney failure.

If you’re concerned about kidney problems, talk with your care team so you can get tested and treated for any kidney issues as soon as possible.

6. Sun or Light Sensitivity

If you’re feeling unusually hot after being in the sun or bright light, photosensitivity — or sensitivity to sunlight and ultraviolet (UV) light — may be the cause.

Photosensitivity is common among people living with lupus. For some, sun exposure can trigger a lupus flare. It may also make your body feel hotter than expected, sometimes even leading to a fever.

Other possible symptoms of photosensitivity include:

• Skin rash
• Fatigue
• Joint pain during or after light exposure

Limiting your exposure to ultraviolet (UV) light may help curb photosensitivity. You can lower your chances of experiencing a flare-up or photosensitive symptoms by wearing sunscreen and protective clothing (like long sleeves and a hat) and by staying in shaded areas to reduce sun exposure.

7. Medications

Some prescription drugs can cause lupus, which is referred to as drug-induced lupus. Drug-induced lupus is not the same as SLE, but they share some symptoms, including fever.

Medications most commonly associated with drug-induced lupus include:

• Hydralazine, which treats high blood pressure
• Isoniazid, which treats tuberculosis
• Procainamide, which treats abnormal heart rhythms

Symptoms of drug-induced lupus can take a long time to appear — sometimes months or even years after starting a medication. Fever is one possible symptom. In most cases, stopping the medication leads to symptom improvement or complete relief.

Talk With Your Doctor About Possible Causes

If you're living with lupus and often feel unusually hot — whether your whole body or just certain areas feel like they’re on fire — there may be several possible reasons. Try to notice when these sensations occur and share any patterns with your healthcare provider. Feeling overheated could be an early sign of a lupus flare or a signal that your body is fighting an infection, especially if your immune system is weakened by medication.

Your healthcare provider can help you figure out what’s behind these symptoms and work with you to find ways to feel more comfortable.

Find Your Team

On MyLupusTeam, people share their experiences with lupus, get advice, and find support from others who understand.

Have you ever felt like your whole body is burning from the inside out? Let others know in the comments below.