🦠 Common Infections in Adults: From Cold to Pneumonia
Symptoms, treatment, and prevention of the infections you're most likely to encounter — reviewed by Dr. Ravi Sishir Reddy, MD
Medically reviewed by: Dr. Ravi Sishir Reddy, MBBS, MD (General Medicine)
Last updated: [Insert Date] | All content in this pillar is reviewed by Dr. Reddy.
📊 Common Infections at a Glance
- Viral infections (cold, flu, COVID‑19, dengue, chikungunya) are usually self‑limiting and do not need antibiotics.
- Bacterial infections (strep throat, UTI, pneumonia, typhoid) often require targeted antibiotic treatment.
- Early recognition of warning signs — high fever, breathing difficulty, confusion, severe pain — can prevent complications.
- Vaccination (flu, pneumonia, COVID‑19) and good hygiene are the best defences.
From the sniffles of a common cold to the high fever of dengue, infections are a part of daily life — especially in a densely populated, tropical country like India. Most are mild and self‑limiting, but some can become serious if not recognised and treated promptly. This pillar guide, reviewed by Dr. Ravi Sishir Reddy, provides clear, concise information on the most common infections affecting adults, organised by the body system they primarily affect.
In This Guide:
- Common Cold: Symptoms & Treatment
- Influenza (Flu): Symptoms & Vaccine
- Dengue Fever: Symptoms & Platelet Count
- Malaria: Symptoms & Diagnosis
- Typhoid Fever: Causes & Treatment
- Chikungunya: Joint Pain Management
- Urinary Tract Infection (UTI)
- Gastroenteritis (Stomach Flu)
- Sinusitis vs Common Cold
- Bronchitis: Acute & Chronic
- Pneumonia: Warning Signs
- Tonsillitis & Pharyngitis
- Ear Infection (Otitis Media)
- Conjunctivitis (Pink Eye)
- Skin Infections: Cellulitis & Boils
1. Common Cold: Symptoms & Treatment
The common cold is the most frequent viral infection in humans, caused by rhinoviruses and coronaviruses. Learn how to manage symptoms, when a cold isn't "just a cold," and why antibiotics don't help.
2. Influenza (Flu): Symptoms & Vaccine
Influenza is not the same as a bad cold. It hits suddenly with high fever, severe body aches, and fatigue, and it can be deadly in vulnerable populations. Learn the symptoms, the importance of annual vaccination, and when antiviral treatment is needed.
3. Dengue Fever: Symptoms & Platelet Count
Dengue is a mosquito‑borne viral illness endemic to India. The hallmark "break‑bone" fever, rash, and dropping platelet count are key features. Know the warning signs that indicate severe dengue and when hospitalisation is needed.
4. Malaria: Symptoms & Diagnosis
Caused by Plasmodium parasites and transmitted by Anopheles mosquitoes, malaria presents with cyclic fevers, chills, and sweats. Early diagnosis with a blood smear or rapid test is crucial — untreated falciparum malaria can be fatal.
5. Typhoid Fever: Causes & Treatment
Typhoid, caused by Salmonella Typhi, is spread through contaminated food and water. It presents with a gradually rising fever, abdominal pain, and a coated tongue. Prompt antibiotic treatment is essential to prevent intestinal perforation.
6. Chikungunya: Joint Pain Management
Transmitted by the same mosquitoes that carry dengue, chikungunya causes high fever and severe, often debilitating joint pain that can last for months. While the acute illness resolves, managing the lingering joint symptoms is a challenge Dr. Reddy addresses.
7. Urinary Tract Infection (UTI)
UTIs are extremely common, especially in women. Symptoms include burning during urination, frequent urges, and lower abdominal pain. If untreated, the infection can ascend to the kidneys, causing a serious systemic illness. Learn when antibiotics are needed and how to prevent recurrence.
8. Gastroenteritis (Stomach Flu)
Vomiting, diarrhoea, and abdominal cramps — gastroenteritis is miserable but usually self‑limiting. The key is preventing dehydration with ORS. Learn when it's viral, when it's bacterial (dysentery), and when you need medical help.
👉 Read more: Gastroenteritis →
9. Sinusitis: How It Differs from a Cold
When a cold lasts too long, it can turn into sinusitis — inflammation of the sinus cavities. Thick nasal discharge, facial pain, and pressure are the clues. Most cases are viral, but a bacterial sinusitis may need antibiotics.
10. Bronchitis: Acute & Chronic
Acute bronchitis, often triggered by a viral respiratory infection, causes a hacking cough that may linger for weeks. Distinguishing it from pneumonia is essential. Chronic bronchitis is a form of COPD and is largely smoking‑related.
11. Pneumonia: Warning Signs in Adults
Pneumonia is a lung infection that can be viral or bacterial. Fever, cough with phlegm, chest pain, and shortness of breath are typical. It can become life‑threatening, especially in the elderly. Know the red flags.
12. Tonsillitis & Pharyngitis (Sore Throat)
Most sore throats are viral. But when it's caused by Streptococcus bacteria — with pus on the tonsils and tender lymph nodes — antibiotics are needed to prevent rheumatic fever. Learn to distinguish the two.
13. Ear Infection (Otitis Media) in Adults
While more common in children, adults can also get middle ear infections — often causing ear pain, a feeling of fullness, and reduced hearing. Learn when antibiotics are indicated and when "watchful waiting" is appropriate.
14. Conjunctivitis (Pink Eye)
Red, itchy, watery eyes — conjunctivitis can be viral, bacterial, or allergic. It's highly contagious in its viral and bacterial forms. Learn how to tell the difference and how to prevent spreading it to others.
15. Skin Infections: Cellulitis, Boils & Abscesses
A small break in the skin can allow bacteria to enter, causing cellulitis (a spreading red, warm, painful area) or a boil (a pus‑filled abscess). These require prompt antibiotic treatment and sometimes surgical drainage.
👉 Read more: Skin Infections →
Knowledge is the first line of defence. The articles above provide the essential information you need to recognise, manage, and prevent the most common infections affecting adults. Always consult your doctor for a proper diagnosis and treatment plan.
📋 Medical Disclaimer
This article is for educational purposes only and does not substitute for professional medical advice. All content is reviewed by Dr. Ravi Sishir Reddy. If you suspect an infection, consult your physician for proper diagnosis and treatment.