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Have you been experiencing a fever repeatedly without knowing why? You're not alone. Repeated fever in adults can be perplexing, exasperating, and occasionally alarming — particularly when there's no clear explanation.
In this blog, we're going to look at the six most likely reasons for adults experiencing recurring fever, and what you need to do next.
Fever is your body's normal reaction to infections or inflammation. It normally resolves in a few days after the immune system battles the issue. But if the fever repeatedly returns over weeks or days, it could be a recurring fever.
This is not always a bad thing, but it does mean your immune system is being continually triggered by something — such as an infection, chronic disease, or underlying inflammation.
Recurrent fever in adults is generally characterized by:
Two or more episodes of fever over several weeks
Normal temperature between fever bouts
Each fever lasting a few hours to a few days
Let us now discuss the most prevalent reasons behind such fevers.
One of the most frequent reasons recurrent fever occurs is the presence of a chronic or ongoing infection. In contrast to common cold or flu, which resolve within a few days, certain infections linger in the body for several weeks or even months.
Frequent chronic infections that lead to recurrent fever in adults:
Tuberculosis (TB): Bacterial infection of the lungs that can also affect other organs. Symptoms are low-grade fever in the evening, cough, weight loss, and night sweats.
Urinary tract infections (UTIs): UTIs, if not treated entirely, may continue to recur and result in recurrent bouts of fever, burning while urinating, and pain in the abdomen. Read more on UTI testing
Hepatitis B or C: These viral liver infections may result in fatigue, fever, yellow eyes, and dark-colored urine.
Relapse of typhoid: Occasionally, relapse of typhoid fever occurs if antibiotics were not finished or if the bacteria persisted in the gut.
Abscess or occult infection: Deep tissue abscess (pocket of pus) in the liver, kidney, or brain can cause persistent low-grade fever.
If your fever has been recurring for over 2–3 weeks, it's crucial to meet a physician and undergo blood investigations, urine tests, and imaging (such as X-ray or ultrasound) to exclude underlying infections.
Visit Blal Lab test directory for related diagnostics.
Autoimmune diseases are conditions where your immune system attacks your own body by mistake. This causes ongoing inflammation, which can cause recurring fever in adults without any apparent infection.
Some of the common autoimmune disorders associated with recurrent fevers:
Systemic lupus erythematosus (SLE): Produces joint pain, rashes, fatigue, and frequent low-grade fever.
Rheumatoid arthritis (RA): Famous for producing swelling and stiffness in joints, but in a few instances, fever is the initial symptom.
Inflammatory bowel disease (IBD): Disorders such as Crohn's disease or ulcerative colitis may produce gastrointestinal symptoms in combination with repeated fevers.
Vasculitis: Inflammation of the blood vessels and can result in fever, fatigue, and damage to organs.
These diseases are difficult to diagnose since symptoms recur and can imitate other diseases.
If you experience persistent fever combined with joint pain, skin rashes, fatigue, or generalized body pain, see a rheumatologist. Blood tests such as ANA, CRP, and ESR can diagnose autoimmune conditions.
You can book inflammation markers like CRP test at Blal Lab.
All infections are not treatable with the initial dosage of medicine. At times, the virus or bacteria develops resistance to the drug or shelters itself deep within the body tissues, still causing fever and inflammation.
These are some cases where this could happen:
Antibiotic resistance: Misuse or abuse of antibiotics has resulted in bacteria that are no longer responsive to medication.
Surgical or dental hidden infection: Occasionally, small procedures result in slowly developing infections that create frequent fever in adults.
Fungal infection: Fungal infections such as histoplasmosis or candidiasis can be the cause in individuals with compromised immune systems or diabetes.
Parasitic infection: Illnesses like malaria or dengue (particularly if you live in or have just returned from tropical regions) can come and go.
Describe your complete history of health to your physician, such as recent travel, surgery, or exposure to new environments. Laboratory tests like blood cultures, stool/urine microscopy, or specialty imaging may be required.
While not that typical, certain forms of cancer may induce fever as a precursor symptom — most notably blood cancers such as leukemia or lymphoma. The fever can recur and disappear, and there can be no apparent symptoms at first.
Other causes of recurring fever related to the blood in adults:
Lymphoma: Typically results in night sweats, enlarged lymph nodes, and recurrent low-grade fever.
Leukemia: Can appear as fatigue, bruising, and fever caused by an impaired immune system.
Myelodysplastic syndromes (MDS): A collection of disorders in which the bone marrow fails to produce normal blood cells.
In the majority of these illnesses, the immune system is depressed, either as a result of the disease or treatment, so the body is more susceptible to infections that cause fever.
If persisting fever is joined by unexplained weight loss, persistent weakness, or enlarged lymph nodes, it is wise to see a hematologist or oncologist. Diagnosis can include blood work, bone marrow biopsy, and imaging studies.
Diabetes, thyroid disease, kidney, or liver disease may at times cause fevers as a result of systemic stress, impaired immunity, or secondary infections.
Diabetes: Low blood sugar compromises the immune system, leading to increased risk of UTIs, skin infections, and foot infections.
Hyperthyroidism: Hyperthyroidism can lead to heat intolerance and low-grade fevers.
Chronic kidney disease (CKD): Blood toxins due to impaired kidney function result in inflammation and fever.
Liver cirrhosis: Increases you to spontaneous bacterial infection and fever.
These fever conditions are not necessarily directly related to the disease but to complications.
Ensure your chronic disease is well controlled. Follow up with your doctor regularly and monitor sugar levels, thyroid profile, kidney/liver function tests to avoid flare-ups.
Explore thyroid profile and liver function test (LFT) on Blal Lab.
Post-pandemic, long COVID and post-viral fatigue syndrome have become prominent causes of recurring fever in adults.
A lot of people recuperating from COVID-19, dengue, or viral flu suffer from:
Low-grade fever intermittently for weeks
Body aches and tiredness
Brain fog or trouble concentrating
Sleep disturbances
These symptoms can persist for 4–12 weeks or more. It isn't that the infection persists, but your immune system is still in hyperdrive and recovering.
Rest, hydration, good sleep, and immune-resilience nutrition are key. Seek the advice of a physician if symptoms don't resolve after a month or if new symptoms arise.
Though fever every now and then might not be a concern, chronic fever in adults should never be dismissed — particularly when it lasts over 2–3 weeks.
Fever recurring more than two times per month
Fever persisting longer than 3 days on each occasion
Night sweats or chills
Unintentional weight loss
Tiredness, rashes, or joint pain
Swollen glands or body aches
Your doctor could recommend:
Blood work (CBC, ESR, CRP)
Urine analysis
Chest X-ray or ultrasound
Infection-specific tests (malaria, TB, typhoid, dengue)
Autoimmune panels
Invasive scans (CT/MRI) as required
You can book a complete fever profile panel at Blal Lab.
Treatment varies with the cause. Your physician will first determine the cause of the fever and then select the appropriate treatment.
Treatments may involve:
Antibiotics or antivirals for infections
Anti-inflammatory or immune-suppressing medication for autoimmune disorders
Insulin or thyroid medication for hormonal reasons
Specific cancer treatment if there is a blood disorder involved
Supportive treatment such as fluids, rest, and antipyretics like paracetamol
Never self-medicate or continue taking fever pills without diagnosis — it may cover up symptoms and hold up treatment.
There's no one reason why fever returns again and again in adults. At times, it's an ongoing infection; at times, it's the immune system playing tricks. What you mustn't do is take the symptoms for granted.
Frequent fever is perhaps not indicative of a fatal disease all the time, but it does suggest something is amiss inside. Early probing, adequate rest, and timely medical intervention can restore you to good health sooner.
If you’ve been struggling with fever that comes and goes, don’t delay — get evaluated and let your body heal with the support it needs.
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