Constant phlegm in your throat and you don’t know why… See more

Common Causes of Constant Phlegm

1. Postnasal Drip

The most common cause is Postnasal Drip. Mucus from the nose and sinuses drips down the back of the throat, creating a constant need to clear it.

Possible triggers:

• Seasonal allergies
• Dust or pet allergies
• Sinus infections
• Chronic rhinitis

2. Acid Reflux

Gastroesophageal Reflux Disease (GERD) or “silent reflux” can irritate the throat and stimulate mucus production.

Other clues:

• Heartburn
• Sour taste in the mouth
• Hoarseness
• Symptoms worse after meals or when lying down

3. Allergies

Environmental allergies can cause ongoing inflammation and excess mucus production.

Common triggers:

• Pollen
• Dust mites
• Mold
• Pet dander

4. Respiratory Infections

After a cold, flu, or other respiratory infection, mucus production can remain elevated for weeks.

5. Smoking and Irritants

Smoking, vaping, air pollution, chemical fumes, and dust can all irritate the airways and increase phlegm production.

6. Asthma

Asthma sometimes presents with throat clearing, coughing, or excess mucus rather than obvious wheezing.

7. Dehydration

Not drinking enough fluids can make mucus thicker and more noticeable.

What May Help

• Drink adequate water throughout the day.
• Use a saline nasal rinse if nasal congestion or postnasal drip is present.
• Avoid smoking and secondhand smoke.
• Consider whether allergies may be contributing.
• If reflux is suspected, avoid large meals before bedtime and limit foods that trigger symptoms.

When to See a Doctor

Seek medical evaluation if:

• Symptoms last more than several weeks.
• You cough up blood.
• You have unexplained weight loss.
• You develop shortness of breath.
• You have persistent hoarseness.
• The symptoms are getting progressively worse.

A Useful Clue

The most likely cause often depends on accompanying symptoms:

If you tell me:

• Your age
• How long you’ve had the phlegm
• Whether you have heartburn, nasal congestion, coughing, or smoking history

I can help narrow down the most likely cause.