Treatment of phlegm stuck in throat

Postnasal drip: This is when mucus drips down the back of your throat from your nose. It can be caused by allergies, a cold, the flu, or sinusitis.
Dry air: Dry air can irritate your throat and make your phlegm thicker and harder to cough up.
Smoking: Smoking damages the airways and can cause excessive mucus production.
Acid reflux: Stomach acid can irritate your throat and cause inflammation, which can lead to phlegm production.
Certain medications: Some medications, such as beta-blockers and ACE inhibitors, can cause a side effect of phlegm production.

Treatment options:
Over-the-counter medications: Decongestants can help to reduce mucus production, while expectorants can help to loosen mucus and make it easier to cough up.
Home remedies: There are a number of home remedies that can help to soothe a sore throat and loosen phlegm, such as gargling with salt water, drinking warm liquids, and using a humidifier.
Prescription medications: If your phlegm is caused by an underlying medical condition, such as allergies or sinusitis, your doctor may prescribe medication to treat the underlying condition.

It is important to see a doctor if your phlegm is accompanied by any of the following symptoms:
Fever
Difficulty breathing
Chest pain
Coughing up blood
Wheezing

I hope this information is helpful.
Please note that I am not a medical professional and this information should not be taken as medical advice. Please consult with your doctor for diagnosis and treatment of any medical condition.