What causes loss of smell?

Under normal circumstances, loss of smell may be caused by upper respiratory tract infections, sinusitis, allergic rhinitis, acute rhinitis, atrophic rhinitis, or other conditions. Patients should promptly visit a正规 hospital to determine the underlying cause and receive appropriate treatment. Specific analyses are as follows:

1. Upper Respiratory Tract Infection

Upper respiratory tract infections are usually caused by viral infections, leading to nasal mucosal congestion and swelling, increased nasal secretions, resulting in nasal obstruction and olfactory disturbances, causing patients to lose their sense of smell. Patients can take medications such as acetaminophen tablets, ibuprofen tablets, or compound licorice tablets under medical guidance. Additionally, maintaining proper warmth in daily life is recommended.

2. Sinusitis

Sinusitis is often caused by pathogenic organisms such as *Streptococcus pneumoniae* or *Staphylococcus*. Inflammation and swelling of the nasal mucosa occur in patients with sinusitis, accompanied by accumulation of nasal secretions, leading to nasal blockage. This obstruction may further result in conductive hyposmia, causing loss of smell. Patients can use medications such as Biyuan Tongqiao Granules, cefixime capsules, or Tongqiao Biyan Tablets as directed by a physician.

3. Allergic Rhinitis

Allergic rhinitis occurs when the body mounts an excessive immune response after exposure to certain allergens such as pollen, dust mites, or animal dander. This leads to inflammation of the nasal mucosa, causing swelling and congestion, which reduces olfactory function and results in the aforementioned symptoms. Patients may take oral antihistamines such as loratadine tablets, cetirizine hydrochloride tablets, or ebastine tablets under medical supervision.

4. Acute Rhinitis

Acute rhinitis is typically caused by viruses or bacteria invading the nasal cavity and multiplying extensively. These pathogens trigger inflammatory responses in the nasal mucosa, damaging the olfactory mucosal areas and leading to loss of smell. Under medical guidance, patients may use medications such as oseltamivir phosphate granules, Siji Kangbingdu Oral Liquid, or Pudilan Xiaoyan Oral Liquid to alleviate symptoms.

5. Atrophic Rhinitis

This condition may result from vitamin deficiencies, endocrine dysfunction, environmental factors, or chronic inflammation, all of which can lead to atrophy of the nasal mucosa. Damage to the mucosal tissue in olfactory regions impairs olfactory function, thus causing the symptoms described above. Patients can use medications such as mometasone furoate nasal spray, fluticasone propionate nasal spray, or oxymetazoline hydrochloride nasal spray as prescribed by a doctor.

In daily life, it's important to maintain healthy habits, follow a regular作息 schedule, ensure sufficient sleep, and support overall physiological health. Regular physical exercise should also be emphasized to enhance personal immunity.