Constant phlegm in your throat can have several causes. The phrase “you don’t know why” is a common clickbait hook, but there isn’t one single explanation.
Some of the most common causes include:
- Postnasal drip: Mucus from the nose or sinuses drains into the throat. This is often due to allergies, a cold, or sinus inflammation.
- Gastroesophageal reflux disease (GERD): Stomach acid can irritate the throat, causing the sensation of mucus, frequent throat clearing, or a lump in the throat.
- Allergic rhinitis: Allergies can increase mucus production.
- Chronic sinusitis: Ongoing sinus inflammation can lead to persistent mucus drainage.
- Smoking or exposure to irritants such as dust or air pollution.
- Dehydration, which can make mucus thicker and harder to clear.
What may help
- Drink plenty of fluids to keep mucus thin.
- If allergies are a trigger, reducing exposure to allergens and discussing treatment with a healthcare professional may help.
- If reflux is suspected, avoiding large meals before bedtime, limiting trigger foods, and elevating the head of the bed can reduce symptoms.
- Avoid smoking and secondhand smoke.
When to seek medical advice
See a healthcare professional if:
- The phlegm lasts more than 3–4 weeks without improvement.
- You cough up blood.
- You have persistent fever, unexplained weight loss, or significant difficulty swallowing.
- You develop shortness of breath or chest pain.
- The mucus is persistently foul-smelling or accompanied by severe facial pain, which could suggest an infection.
Most cases of persistent throat phlegm are not serious, but if it’s ongoing or accompanied by other concerning symptoms, it’s worth getting evaluated to identify and treat the underlying cause.
