🫁 Respiratory

Pneumonia

Infection of the lung tissue causing cough, fever and breathlessness.

Overview

Pneumonia is inflammation of lung tissue, most often from bacterial or viral infection. Severity ranges from outpatient illness to life-threatening sepsis.

Symptoms

  • Productive cough
  • Fever, chills
  • Pleuritic chest pain
  • Breathlessness
  • Fatigue

Risk factors

  • Age >65 or <2
  • Smoking
  • COPD or asthma
  • Immunosuppression
  • Recent viral illness

Causes

  • Streptococcus pneumoniae and other bacteria
  • Influenza, RSV, COVID-19
  • Aspiration

🚨 Red flags — seek urgent care

  • Respiratory rate >30
  • Oxygen saturation <92%
  • Confusion
  • Low BP
  • Cyanosis

When to seek care

  • High fever with breathlessness
  • Coughing blood
  • Worsening symptoms after 48 hours

Diagnosis

  • Acute cough plus ≥1 of: fever, pleuritic chest pain, dyspnoea, focal chest signs
  • Chest X-ray for confirmation in moderate–severe disease or diagnostic uncertainty
  • CRP and CURB-65 (or CRB-65 in community) to grade severity
  • Microbiology: sputum culture, blood cultures, urinary antigens (Legionella, pneumococcus) in moderate–severe disease

Treatment

  • CRB-65 0 (low risk): amoxicillin 500 mg TDS for 5 days (doxycycline/clarithromycin if penicillin-allergic)
  • CRB-65 1–2 (moderate): dual therapy with amoxicillin + macrolide for 5–7 days
  • CRB-65 3–4 (severe): hospital IV antibiotics (e.g. co-amoxiclav + clarithromycin), oxygen, IV fluids
  • Atypical cover (macrolide or doxycycline) when atypical pathogens suspected
  • Review at 48–72 h; escalate if not improving

Prevention

  • Annual influenza vaccine; pneumococcal vaccine for at-risk groups and adults ≥65
  • Smoking cessation
  • COVID-19 vaccination per current schedule
  • Hand hygiene; treat dental disease

Complications

  • Parapneumonic effusion and empyema
  • Lung abscess
  • Sepsis and septic shock
  • Respiratory failure (Type 1)
  • Post-pneumonia chronic fatigue / cardiovascular events

Education & self-care

Vaccination against pneumococcus and influenza substantially reduces risk, particularly in older adults and those with chronic disease.

Frequently asked questions

Do I always need antibiotics?

Bacterial pneumonia needs antibiotics. Viral pneumonia is treated supportively.

How long does recovery take?

Cough and fatigue often persist 3–6 weeks even after successful treatment.

How long is recovery?

Cough and fatigue can persist for weeks even after antibiotics finish. Chest X-ray changes can take 6 weeks or more to clear; a follow-up X-ray is often offered to confirm resolution.

Do I need to be in hospital?

Most community-acquired pneumonia is treated at home. Severity scores (CRB-65 or CURB-65) and oxygen saturation help decide who needs admission.

Can pneumonia be prevented?

Pneumococcal and annual flu vaccines significantly reduce risk in older adults, smokers and those with chronic disease. Stopping smoking is the single most effective preventive measure.

Medically reviewed by Dr. Handel Emery, MD, FRCP (UK) · Last reviewed 2026-06-08