It is totally normal to have some coughing after a hard laugh. The best explanation for why this happens is that the nerves that are involved in the laughing reflex are the same nerves that are involved in the coughing reflex. Therefore, triggering of one of these reflexes (laughing) can cause spill over into the other reflex (coughing). This happens to many people and does not at all mean that you have an underlying medical problem.
On the other hand, if you have fits of coughing also at other times (not just while laughing) then this is something you might want to have investigated.
A common cause of chronic coughing fits is smoking. However, if you do not smoke then there are several other possible causes.
These include nasal allergies, or allergic rhinitis, which causes inflammation of the lining of the nasal passage leading to dripping of mucus down the throat and a chronic irritating cough. It can be easily treated by your doctor
with nasal steroid sprays and antihistamines.
Another common cause of chronic cough is asthma
. Although we often think of asthma as causes wheezing, sometimes it presents only with cough, especially cough at night or with exercise. Your primary care doctor
can diagnose this and provide you with treatment if necessary.