Usually, after a week or so, the cold runs its course and most of the symptoms go away. But for some people, the cough hangs around a little longer.

So why do we cough and what can we do about it?

Coughing is a protective reflex

Humans developed the ability to cough over time to do a number of things. One is to eliminate things that are in the lungs that cause irritation. We have learned to cough to expel the mucus that may be down there. Another is to protect your airway from anything going into your lungs so you don’t choke.

The cough could be due to an upper respiratory tract infection

Sometimes there’s still some residual airway inflammation in the lungs from typical upper respiratory tract infections. So even after the real meat of the infection is gone and you’re starting to feel better, you have this cough because you still have some inflammation in the lungs. The lungs are quite sensitive, so when they are inflamed and irritated, it doesn’t take a lot to cause a cough.

Coughing can be worse at night

If you’ve got an upper respiratory tract infection with any kind of sinus congestion or runny nose, when you lay down to go to bed, the mucus drains down the back of your throat on top of your upper airway, which causes you to cough.

Coughing at night is more disruptive because you’re trying to sleep. If you’re coughing throughout the day, you cough and you continue with your activities. When you’re trying to fall asleep, coughing can make it really hard to sleep, so it’s more irritating and frustrating for you and, potentially, your bed partner.

If you’ve been coughing for more than three weeks, you may have a chronic cough

When you’re in the middle of an infection and you’re coughing, it doesn’t seem like it’s ever going to end. It’s frustrating but it’s a normal, protective and self-limited reflex.

If you’re still coughing and feeling sick after three weeks, then you should probably be evaluated. Make an appointment to see your primary care doctor. If necessary, your primary care doctor will refer you to a pulmonologist.

A persistent cough could be a symptom of a serious illness

There are warning signs that you should seek medical care for a persistent cough before three weeks have past.