Why haven't I recovered several months after testing negative for COVID-19?

　　"Yang Kang" generally refers to the period after recovery from a novel coronavirus infection. If symptoms persist for several months following infection, this may be related to conditions such as respiratory tract infections, cough-variant asthma, or postnasal drip syndrome. Specific causes are analyzed as follows:

　　1. Respiratory Tract Infection

　　After a novel coronavirus infection, respiratory tract infections may occur. This condition can lead to damage of the tracheal and bronchial mucosa and non-specific airway inflammation due to the infection. Under medical guidance, medications such as dextromethorphan, loratadine, and chlorpheniramine maleate may be used for treatment.

　　2. Cough-Variant Asthma

　　This is generally one of the causes of chronic cough. For this issue, medications such as montelukast sodium, salbutamol, terbutaline, and fluticasone propionate inhalation aerosol may be used under a doctor's advice.

　　3. Postnasal Drip Syndrome

　　This condition is usually caused by other diseases, such as rhinitis, sinusitis, or allergic rhinitis. When these conditions occur, secretions from the back of the nasal cavity may drip down into the pharynx, causing coughing. For rhinitis, antihistamines such as chlorpheniramine maleate or ebastine may be used to improve symptoms.

　　In addition, persistent symptoms may also be caused by other conditions such as chronic pharyngitis or tracheitis. If adverse symptoms continue after recovery from a novel coronavirus infection, patients are advised to seek timely medical evaluation at a reputable hospital to determine the underlying cause and receive targeted treatment, thus avoiding delays in care.