Constant phlegm in your throat is common, but it can have several different causes. The most likely ones include:
- Postnasal drip: mucus draining from the nose or sinuses into the throat, often from allergies, a cold, or sinus irritation.
- Acid reflux: reflux can irritate the throat and cause mucus, throat clearing, coughing, or hoarseness—even without obvious heartburn.
- Allergies or nasal irritation: pollen, dust, smoke, pollution, and dry air can increase mucus production.
- Asthma or other airway conditions: especially when phlegm occurs with coughing, wheezing, or breathlessness.
- Smoking or vaping: these can irritate the airways and increase mucus.
- A lingering infection: mucus and coughing can remain for a while after a respiratory infection.
What may help
Drink enough water, avoid smoking and secondhand smoke, use a humidifier if the air is very dry, and consider saline nasal rinsing if nasal congestion or postnasal drip is involved. If reflux seems likely, avoid large meals close to bedtime and identify foods that trigger symptoms.
Don’t assume that green or yellow mucus automatically means you need antibiotics.
If the problem persists for several weeks, keeps getting worse, or is accompanied by shortness of breath, chest pain, unexplained weight loss, persistent fever, difficulty swallowing, or blood in the phlegm, get medical evaluation.
