Why is the phlegm expelled from H1N1 influenza thick and yellow, and what should be done?

Generally speaking, "A flu" refers to influenza A. Influenza A is a respiratory infectious disease caused by the influenza A virus. If someone with influenza A coughs up thick, yellow phlegm, this may be due to the natural course of an inflammatory response, phlegm concentration, acute bronchitis, sinusitis, pneumonia, or other causes. Treatment options include general care and medication under a doctor's guidance. If discomfort occurs, prompt medical attention is recommended. Detailed explanations are as follows:

1. Natural Course of Inflammatory Response

After infection with the influenza A virus, the respiratory mucosa is stimulated, triggering an inflammatory response that leads to increased mucus secretion. As the condition progresses, the phlegm may gradually become thicker and turn yellow, a result of the mixture of white blood cells and shed epithelial cells during the inflammatory process. It is recommended to maintain a healthy lifestyle, including a balanced diet, moderate exercise, adequate sleep, and stress reduction, to enhance immune function.

2. Phlegm Concentration

During influenza A, patients may lose excessive body fluids due to fever and sweating, leading to concentrated phlegm and a yellowish color. It is recommended to drink plenty of water to maintain adequate hydration, which helps thin the phlegm.

3. Acute Bronchitis

Acute bronchitis may be caused by the influenza A virus or secondary bacterial infection, leading to airway inflammation and increased secretions. The mixture of white blood cells and pathogens may result in thick, yellow phlegm. Symptoms may include cough, chest tightness, and mild fever. Patients may follow medical advice to use medications such as amoxicillin-clavulanate potassium tablets, ambroxol hydrochloride oral solution, or acetylcysteine granules.

4. Sinusitis

Sinusitis is an inflammatory disease of the nasal sinus mucosa, usually caused by bacterial infection. During an influenza A infection, infection with pathogens such as Staphylococcus aureus or Streptococcus pneumoniae may trigger sinusitis. Postnasal drip may irritate the throat, causing the patient to cough up yellow, viscous phlegm. Symptoms may also include nasal congestion, runny nose, and impaired sense of smell. Patients may use medications such as cefixime capsules, budesonide nasal spray, or eucalyptus oil soft capsules under medical guidance to relieve symptoms.

5. Pneumonia

Pneumonia is mainly caused by viral or bacterial infections. Influenza A-induced immune suppression may lead to pneumonia. The inflammation affects the lung tissue, causing increased exudate in the alveoli, mixed with shed epithelial cells and inflammatory cells, forming thick, yellow phlegm. Accompanying symptoms may include high fever, difficulty breathing, and chest pain. Patients are advised to follow medical guidance for treatment with medications such as levofloxacin tablets, azithromycin tablets, or penicillin G sodium for injection.

If symptoms of influenza A occur, timely medical attention should be sought, and treatment should be followed as directed by a physician to prevent worsening of the condition. Additionally, maintaining good personal hygiene habits, such as frequent handwashing and wearing a mask, is recommended.