Thanks for the query
Headache can be due to various causes.
You need clinical and detailed evaluation by a neurologist
Note that nitroglycerin
itself can be the cause of headache
Please visit a local neurologist and get examined. He after examining will let you know the requirement of brain scan to rule out secondary causes of headache like tumor
, infection, problem in the blood vessel etc.
If everything is normal, try to know the exact need of nitroglycerine (from the doctor who has advised)
I think you have headache related to nitroglycerine; though other causes cannot be excluded without any evaluation
Hope this clarifies