Brief Answer:
Needs to find the etiology, symptomatic treatment till then

Detailed Answer:
Thank you for asking

i read your question and i understand your concern. Sinuses infections and allergies despite being resolved leaves an irritation of airways enough for the cough to recur. The most common cause of chronic cough is predictable. It's the aftermath of a cold or other viral infection, says XXXXXXX H. Edelman, MD, chief medical officer of the XXXXXXX Lung Association. Most cold symptoms may go away after a few days. Your cough, though, can hang around for weeks, sometimes for months, because viruses can cause your airways to become swollen and oversensitive. This can last long after the virus is gone.

apart from it, Allergies and asthma are common causes of a cough. A cold can even cause an asthma attack. Some people learn they have asthma during a cold.

Acid reflux and obstructive sleep apnea can also cause a chronic cough. Fortunately, these conditions are treatable. See your doctor for diagnosis and treatment if you have symptoms of acid reflux, including:

Burping
Heartburn
Ongoing cough
Regurgitation
Also see your doctor if you have symptoms of obstructive sleep apnea, such as:

Insomnia
Loud snoring
Nighttime choking or gasping
Repeated awakenings
Sleepiness during the day

Stress also causes such cough. Stress, especially when it's chronic, can make colds last longer. To beat back a lingering cough, slow down and ease stress while you're sick. Pushing yourself too hard might just make you sicker. One way to relax is to rest more: Aim for 7 to 8 hours of sleep a night.

Not drinking enough fluids can lead to such chronic cough. When you have a cold or the flu, you need to drink a lot of fluids. Water, juice, and soup can help loosen mucus in your airways so you can cough it up and out. Alcohol and drinks with caffeine in them are not helpful choices because they can dehydrate you -- the opposite of what you need when you're sick. Another way to add moisture to your airways is by using a saline nasal spray.

Overuse of inhalers and decongestant sprays may also cause the cough to occur. Over-the-counter (OTC) nasal decongestant sprays may help with a stuffy or runny nose. Don't use them for more than 3 days, though. If you do, when you finally stop taking them, your symptoms may be worse -- a rebound effect. Those excess sprays make your nasal membranes swell, which triggers more congestion, postnasal drip, and coughing.

Dry air is commonest of all for such irritant cough. "Dry air -- especially common in the winter -- can irritate a cough," Edelman says. On the other hand, cranking up the humidifier too high isn't helpful, either. Moist air can be a trigger for asthma and encourage the growth of dust mites and mold, allergens that may start you hacking.

"People should aim for humidity levels of 40% to 50% in their homes, winter and summer,

Sometimes, a cold can leave behind an unwelcome parting gift. When your airways are raw and irritated after a cold, it's easier for bacteria to invade. Bacteria can cause sinus infections, bronchitis, and pneumonia. If you have a fever or pain along with your lingering cough, a bacterial infection could be the reason. See your doctor, as you may need to take an antibiotic.

Last but not the least. Do you take medicine for high blood pressure? If so, that may be why your cough won't quit. About 1 out of 5 people who take ACE inhibitors develop a chronic, dry cough as a side effect. If you have this side effect, talk to your doctor. Another drug may work better for you. There are many available ACE inhibitors, including:

Altace (ramipril)
Capoten (captopril)
Lotensin (benazepril)
Prinivil, Zestril (lisinopril)
Vasotec (enalapril)
If the generic name of your medicine ends with "pril," there's a good chance it's an ACE inhibitor.

If your cough isn’t getting better after a week, call your doctor. Together, you can find out what’s causing your cough and make sure you get the right treatment.

Use herbal tea with honey in it. Boiled eggs, aspirin gargles and garlic water mouth rinses will suppress the cough. Also try to find the underlying cause and let that be treated accordingly.

I hope it helps. Take good care of yourself and dont forget to close the discussion please.

Regards
Khan

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