Symptoms of bacterial infection

Symptoms of Bacterial Infection

Bacterial infections speak in two voices: local signs where the infection sits, and whole-body signs as the body fights. Learning both - and especially the signs of spread - tells you when home care ends and the doctor begins.

Local Signs: Where the Infection Sits

• Skin and wounds: redness, warmth, swelling, pain, pus, foul smell; red streaks tracking up a limb are a danger sign
• Throat and ear: severe sore throat with pus on the tonsils and high fever (bacterial, not viral, pattern), ear pain with discharge
• Chest: cough with thick yellow-green phlegm, chest pain on breathing, breathlessness (pneumonia pattern)
• Urinary: burning or pain on passing urine, urgency, cloudy or bloody urine, fever with flank pain (kidney involvement)
• Gut: severe diarrhoea - especially with blood or mucus - persistent vomiting, severe abdominal pain (typhoid causes sustained high fever with abdominal symptoms)

Whole-Body Signs

• Fever: often high and persistent; in typhoid a step-ladder rise over days; in TB a low evening fever for weeks
• Chills and rigors: shaking episodes as fever climbs - common in bacterial infections
• Fatigue, body ache, headache, loss of appetite - the general tax of infection
• Sweats: drenching night sweats with weight loss over weeks suggest TB

Danger Signs: When Infection Spreads

Call 112 or 102, or reach an emergency department immediately, for:

• High fever with confusion, drowsiness or difficulty waking
• Rapid breathing, racing heart, very little urine
• Cold, mottled or bluish hands and feet, or a rash of dark spots that does not fade when pressed (possible meningococcal or sepsis rash)
• Severe breathlessness, chest pain, fainting
• In infants: refusing feeds, abnormal drowsiness, persistent high-pitched cry, a bulging soft spot

These are the signs of sepsis and meningitis - conditions where hours decide outcomes. See NHS guidance on sepsis.

The Ayurvedic Perspective

Classical texts listed remarkably precise danger signs (Arishta Lakshana) in severe fevers: continuous high fever with loss of consciousness, delirium (Pralapa), severe breathlessness, cold limbs with burning internal heat, dark spots or blisters on the skin (Kotha), bleeding, unquenchable thirst and rapid wasting - Madhava Nidana, Chapter 2; Charaka Samhita, Chikitsa Sthana 3. Ancient clinicians without a single microscope knew which fevers kill; modern sepsis protocols chase the same signs.

Frequently Asked Questions

Is green phlegm proof of bacterial infection? No - colour alone proves nothing; viral infections also produce coloured phlegm. Duration, fever pattern and examination matter more than the colour chart.

How long is too long for a fever? Any fever beyond 3 days without improvement, fever with danger signs at any point, or fever in an infant under 3 months - all need a doctor. Typhoid and TB classically present as fevers that simply do not settle.

What does a non-fading rash mean? Press a glass against it: a rash that does not blanch (fade) can signal meningococcal sepsis - treat it as an emergency and get to hospital immediately.

Are chills dangerous? Rigors themselves are common with rising fevers, including malaria and urinary infections. Chills plus confusion, breathlessness or the danger signs above make it an emergency.