A nagging cough can be exhausting and frustratingly slow to improve. Figuring out what’s causing your cough can help you find relief.
Here are common reasons you might be experiencing a nagging cough that won’t go away:

Coughs often follow on the heels of a cold or influenza because the viruses associated with these illnesses can irritate the airways and make them overly sensitive. Typically, this type of cough will dissipate over time as the inflammation subsides.

A nagging cough is often associated with a postnasal drip, which is when the body produces excess mucus that runs down the back of your nose to your throat.
Mucus production is a routine bodily function that helps moisten passageways and traps bacteria and viruses before they cause infection. However, under certain circumstances the body will produce excess mucus that can tickle the nerves of the nasopharynx and trigger a cough, says Stephanie Gonshor, a family nurse practitioner at Tidelands Health Family Medicine at Garden City.
For example, people can experience a postnasal drip when suffering from a cold or the flu, due to a sinus infection or sinusitis, as a side of effect of certain medications or because of cold or dry air.

Cold, dry air can also affect the mucus that is commonly present in our lungs, triggering a nagging cough and increasing our risk for illness.
“We have a protective mucus in the lungs, but when it’s cold that mucus thickens and gets stickier, which can harbor more bacteria and increase our risk of infection,” Gonshor says.
Treatment for a postnasal drip will depend on its cause, Gonshor says. If it is due to a bacterial infection, for example, antibiotics can help. Antihistamines and decongestants can be effective if the condition is due to allergies or a viral infection.
For temporarily relief, many people turn to hot showers, soups and drinks, which can help thin out mucus. Nasal saline sprays can also help keep the mucus thinned and flowing, Gonshor says.
Propping up your pillow at night can help, as can the use of a humidifier. However, if your postnasal drip is caused by allergies, a humidifier may circulate allergens in your environment and make the problem worse.

Using an over-the-counter nasal decongestant spray for more than three days can lead to a dependence on the product. When you try to stop after prolonged use, you may face a return of the symptoms or worsening symptoms. That’s because excess use swells nasal membranes, triggering congestion and the postnasal drip, prompting the cough to return or become more severe.

Insufficient rest can put undue stress on your body, especially if you’re battling a cold or other virus. When you’re stressed, it’s more difficult to beat back a stubborn cough. Make sure to always get enough sleep and eat a healthy diet rich in fruits and vegetables.

A lingering cough may also be linked to asthma, acid reflux or obstructive sleep apnea. The good news is that treatment can help address these underlying causes to help resolve the cough. Speak with your family medicine physician or other primary care provider if you think you are suffering from one of these conditions.

Certain ACE inhibitors—medications used to control high blood pressure—can cause some patients to develop a chronic, dry cough. If you suspect that’s the cause of your nagging cough, discuss it with your care provider. There may be an alternative medication that works better for you.

A nagging cough can linger for up to six weeks. It’s important, however, to seek medical care if the cough persists after a week to 10 days or is accompanied by fever, chills, shortness of breath or body aches.
“Without being evaluated, it can be difficult to determine the cause of the cough,” Gonshor says. “If it’s not going away or you have concerns about your symptoms, connect with your care provider to determine if something more is going on. We’re here to help.”