Fever (pyrexia) is a temporary rise in body temperature—usually a sign that your immune system is fighting an infection. The normal oral body temperature for healthy adults is about 36.5–37.5 °C. A body temperature of ≥ 38.0 °C (100.4 °F) is generally considered a fever.
Fever commonly accompanies infectious illnesses such as malaria, dengue, enteric (typhoid) fever, tuberculosis, and various viral or bacterial infections. In most cases, fever is a useful physiologic response, as long as it is not prolonged and does not reach dangerous levels. Very high temperatures (≈ 42 °C / 107.6 °F and above) can be harmful.
This guide explains fever types, symptoms, causes, and home remedies, plus what to eat and avoid.
Types of Fever
A) By duration
- Acute: lasts ≤ 7 days
- Sub-acute: > 7 days up to 14 days
- Chronic / Persistent: > 14 days
B) By temperature level (approximate clinical ranges)
- Low-grade: 37.8–38.3 °C
- Moderate: 38.4–39.4 °C
- High: 39.5–40.9 °C
- Hyperpyrexia (very high): ≥ 41.0–41.5 °C
C) By pattern of temperature
- Intermittent fever: near-normal in the morning, rises later; often seen with malaria or septicemia.
- Classic malaria sub-types: quotidian, tertian, quartan.
- Classic malaria sub-types: quotidian, tertian, quartan.
- Sudden high fever: abrupt onset with fatigue, headache, and body aches; common in dengue and many viral infections.
- Continuous (sustained) fever: remains above normal with < 1 °C variation in 24 h; seen in typhoid, pneumonia, UTI.
- Remittent fever: remains elevated but fluctuates by > 1 °C in 24 h; seen in brucellosis or infective endocarditis.
- Rheumatic fever: an inflammatory condition following group A streptococcal throat infection; can present with sore throat, fever, joint pains, rash, etc.
Other named patterns occasionally reported in India include Pel-Ebstein (classically linked to Hodgkin lymphoma) and neutropenic fever (in patients with very low neutrophil counts).
General Symptoms
- Sweating and chills/rigors
- Headache; muscle and joint pains
- Poor appetite, fatigue, dizziness
- Difficulty concentrating; malaise
- Nausea/vomiting; abdominal cramps
- Skin rashes or red spots (e.g., dengue)
- Light sensitivity
- Fast breathing or shortness of breath
- Dehydration
- Febrile seizures (mostly in young children)
See a doctor urgently if fever lasts > 3 days, is ≥ 39.4 °C (103 °F), or is accompanied by alarm signs (confusion, chest pain, breathing difficulty, persistent vomiting/diarrhea, severe weakness, seizures, rash with bleeding, very low urine output).
If fever persists > 2 weeks, seek medical evaluation for chronic or unusual causes.
What Causes Fever?
- Infections: viral, bacterial, parasitic, or fungal
- Examples: respiratory (flu, pneumonia), GI (gastroenteritis, typhoid), UTI, skin/soft tissue, malaria, TB
- Examples: respiratory (flu, pneumonia), GI (gastroenteritis, typhoid), UTI, skin/soft tissue, malaria, TB
- Inflammatory/autoimmune: rheumatoid arthritis, lupus
- Cancers: e.g., lymphoma, leukemia
- Drugs/substances: some antibiotics, anticonvulsants; stimulants (e.g., cocaine, amphetamines)
- Environmental/heat: heat exhaustion/heat stroke
- Post-vaccine reactions (usually mild and short-lived)
Home Remedies and Self-Care
These can help with mild, uncomplicated fever in generally healthy adults. They do not replace medical care if warning signs are present.
- Herbal decoctions (traditional use):
- Tulsi (holy basil) and bahok leaves (local herbal practices): simmer in water, reduce, sweeten with a small amount of honey; sip warm 1–2× daily for a few days.
- Tulsi + bahok + ginger + long pepper (pippali) + bay leaf: prepare as a light tea and sip morning/evening for 2–7 days.
- Note: Herbal remedies can interact with medicines or be unsuitable in pregnancy, chronic disease, or for children. Use modestly and stop if any irritation/allergy occurs.
- Rest and sleep: your body heals faster at rest.
- Hydration: drink water, oral rehydration, diluted fruit juices, coconut water, or clear soups to prevent dehydration.
- Lukewarm fluids & sponging: use lukewarm (not cold) water for comfort.
- Light, easy-to-digest meals: small frequent portions (see diet section).
- Hygiene: wash hands often; wash clothes/towels in warm water; avoid sharing personal items.
- Dress light: avoid heavy layering that traps heat.
- OTC medicines (use wisely):
- Paracetamol/acetaminophen as first choice, as per label dosing.
- Ibuprofen can help with aches if no kidney disease, ulcers, or NSAID allergy.
- Avoid aspirin in children/teens (risk of Reye’s syndrome). Use naproxen/aspirin cautiously in older adults and those with gastric, kidney, bleeding, or heart issues.
- If you have chronic illness, are pregnant, or take blood thinners, consult a clinician before NSAIDs.
- Paracetamol/acetaminophen as first choice, as per label dosing.
What to Eat—and What to Avoid—During Fever
Prefer (easy on the gut, hydrating, nutritious)
- Water, ORS, diluted fruit juices, tender coconut water
- Rice porridge/khichdi, soft boiled vegetables
- Clear vegetable/chicken soups, broths
- Custard, yogurt/curd (if tolerated)
- Lean proteins: eggs, steamed fish, soft dhal, small portions of lean meat
- Citrus and vitamin-C rich fruits (if tolerated)
Limit/Avoid (hard to digest or irritating)
- Very oily/fried, heavily spiced, or ultra-processed/packaged foods
- High-sugar snacks and drinks
- Excess ghee and very high-fibre roughage when nauseated
- Strongly flavored caffeinated beverages if they worsen dehydration or palpitations.
Tip: Go by tolerance—what feels soothing and stays down. Re-introduce regular foods gradually as you improve.
Conclusion
Fever is usually a self-limited protective response. Support yourself with rest, hydration, and light nutrition, and use paracetamol if needed. Seek medical care if fever is very high, prolonged, or accompanied by warning symptoms. Traditional herbal sips may soothe mild symptoms, but use them sensibly and do not delay proper diagnosis and treatment when indicated.
FAQ
1. Is fever dangerous? Can it harm the brain?
Ans: Fever itself is part of the immune response and is usually not dangerous. Brain injury is rare and typically associated with extreme temperatures (≈ 42 °C / 107.6 °F or higher) or heat stroke, not with common infectious fevers.
2. What commonly causes high temperature?
Ans: Most often viral infections (e.g., common cold, flu). Others include gastroenteritis, ear/sinus infections, pneumonia, UTIs, dengue, malaria, medication reactions, and inflammatory diseases.
3. When does fever become a serious problem?
Ans: Seek care if fever is ≥ 39.4 °C (103 °F), lasts > 3 days, or if you develop confusion, severe weakness, shortness of breath, chest pain, persistent vomiting/diarrhea, bleeding rash, very low urine output, or seizures. Infants, older adults, pregnant people, and those with chronic illnesses should seek earlier evaluation.
4. Which temperature is considered a fever?
Ans: ≥ 38.0 °C (100.4 °F).
5. Can fever cause seizures?
Ans: Febrile seizures occur in about 2–5% of children between 6 months and 5 years. They are frightening but usually brief and do not typically cause long-term harm. Any first seizure warrants urgent medical assessment.
My self Anita Sahani. I have completed my B.Com from Purbanchal College Silapathar. I am working in Dev Library as a Content Manager. A website that provides all SCERT, NCERT 3 to 12, and BA, B.com, B.Sc, and Computer Science with Post Graduate Notes & Suggestions, Novel, eBooks, Health, Finance, Biography, Quotes, Study Materials, and more.
