Respiratory tract infections (RTIs) account for some of the most frequent health complaints in the UK and may affect any age group from infants to older adults. These infections disrupt daily life, sometimes causing either mild or severe symptoms that may require a doctor’s attention. RTIs can be classified commonly into two groups: upper respiratory tract infections (URTIs) and lower respiratory tract infections (LRTIs). The upper respiratory tract consists of the nose, throat, and sinuses, while the lower respiratory tract includes the lungs and bronchi. Common RTIs include the common cold, sinusitis, bronchitis, and pneumonia. Emerging research suggests that some viral RTIs, such as those caused by respiratory syncytial virus (RSV) or human metapneumovirus (hMPV), are increasingly recognised in adults, not just children. Therefore, detecting the symptoms as early as possible is extremely important for treatment and prevention of complications.

Causes of Respiratory Tract Infections

There are microorganisms such as viruses, bacteria, and fungi that are the main causes of RTIs. Most of these infections are viral in nature, and this category includes colds and influenza; however, some bacterial infections, such as streptococcal throat infections and pneumonia, are less common but still occur. Fungal infections are less common, although they can occur in patients with low immunity, such as those with HIV/AIDS or long-term steroid use.

Upper respiratory tract infections, including colds and sinusitis, are spread through droplets from coughing or sneezing, contact with contaminated surfaces or infected people, or direct contact with infected individuals. The main viral pathogen associated with upper respiratory tract infections is rhinoviruses. Lower respiratory infections include bronchitis and pneumonia, which may have a bacterial or viral cause. Newer strains, such as SARS-CoV-2 (responsible for COVID-19), have further emphasised the importance of distinguishing between viral and bacterial RTIs for proper treatment.

Certain conditions increase the risk of developing RTIs, like smoking, chronic illnesses (such as asthma or COPD), weakened immune function due to advanced age, stress, or underlying health conditions. Recent evidence also links air pollution and vitamin D deficiency to increased susceptibility.

Symptoms of Respiratory Tract Infections

1. Symptoms of Upper Respiratory Tract Infections

• Runny or blocked nose
• Sore throat
• Cough
• Headache
• Sneezing
• Mild fever and fatigue

Upper RTIs are typically mild and resolve within a few days. However, they can sometimes lead to complications like sinus infections or ear infections. In some cases, a post-viral cough can persist for weeks due to airway hypersensitivity.

1. Symptoms of Lower Respiratory Tract Infections

• Persistent cough with mucus (classified as a ‘productive cough’ in clinical guidelines)
• Shortness of breath
• Chest pain or tightness
• Wheezing
• High fever, sweating, and fatigue
• In severe cases, bluish lips or fingertips (indicating oxygen deprivation)

Lower RTIs, such as pneumonia or severe bronchitis, can be more serious and may require medical intervention. Recent findings show that some patients with severe pneumonia may develop sepsis, requiring urgent hospital care.

Diagnosis of Respiratory Tract Infections

A doctor will begin the diagnosis with a physical examination, checking for signs like fever, difficulty in breathing, and throat inflammation.

Upper RTIs are primarily diagnosed based on symptoms, and further tests are usually unnecessary. Lower RTIs, however, may warrant further tests or differential diagnoses, including:

• Chest X-rays – to visualise pneumonia or lung infections. High-resolution CT scans are now used in complex cases.
• Blood work – to differentiate infections due to bacteria or viruses. CRP and procalcitonin tests help guide antibiotic use.
• Sputum culture – to identify bacterial causes in cases of persistent cough. Molecular PCR tests are increasingly used for faster results.
• Pulse oximetry – to measure blood oxygen levels in severe lung infections. Home pulse oximeters are now recommended for high-risk patients.

Treatment for Respiratory Tract Infections

1. Treatment for Upper Respiratory Tract Infections
   Most upper RTIs are self-limiting and can be managed with home care:

• Rest and stay hydrated.
• Over-the-counter pain relievers, such as ibuprofen or paracetamol, can reduce fever and discomfort.
• Decongestants and antihistamines can relieve nasal congestion. Nasal saline irrigation is a recommended alternative.
• Antibiotics are prescribed only if a bacterial infection like strep throat is confirmed. Antibiotic stewardship programmes emphasise avoiding unnecessary antibiotic use.

1. Treatment for Lower Respiratory Tract Infections

• Viral lower RTIs: Treated with supportive care, including rest, hydration, and fever reducers. Antivirals (e.g., oseltamivir for flu) may be used in high-risk cases.
• Bacterial infections: Require antibiotic treatment (e.g., amoxicillin for pneumonia). Macrolides or doxycycline are alternatives for penicillin-allergic patients.
• Bronchitis treatment: May include bronchodilators or inhalers to relieve symptoms. Evidence now supports honey as a natural cough suppressant.
• Severe cases: May require hospitalisation for oxygen therapy or IV antibiotics, particularly in pneumonia or cases of breathing difficulty. ICU admission may be required for ARDS (acute respiratory distress syndrome).

Prevention Tips

To reduce the risk of RTIs, consider the following preventive measures:

• Wash hands frequently to minimise germ transmission. Alcohol-based sanitisers are effective when soap isn’t available.
• Avoid close contact with infected individuals. Since the pandemic, wearing masksin crowded places remains advised for vulnerable groups.
• Get vaccinated against flu and pneumonia. RSV vaccines for older adults are available.
• Quit smoking to lower the risk of lower respiratory tract infections. Vaping has also been linked to an increased risk of RTIs.
• Maintain a strong immune system with a balanced diet and regular exercise. Zinc and vitamin C supplementation may help, although evidence is mixed.

Conclusion

Respiratory tract infections vary from mild colds to severe lung infections, such as pneumonia. Recovery from RTIs depends on early recognition of symptoms and prompt treatment. If symptoms are persistent or worsening, medical advice is warranted. Chase Lodge Hospital offers expert care for RTIs, with accurate diagnosis and effective treatment. Our clinic provides rapid PCR testing and tailored management plans based on the latest guidelines. If symptoms are not improving, book a consultation with our clinicians for a personalised approach to your care..