Brief Answer:
Hyperhidrosis, and it is common.

Detailed Answer:
Hello,
Welcome to HCM.
I am Dr Rakesh Sharma answering your query.
I can understand your concern.
This is hyperhidrosis,idiopathic(cause not really known).
Primary hyperhidrosis is localized to a certain part of the body, such as the head, though these symptoms will appear symmetrically when the patient experiences sweat on the limbs. Doctors believe that primary hyperhidrosis is caused by a malfunction in the nervous system that may be genetic. This condition is not dangerous.
It can also be caused as side effect of some medication, though you are not using any medicines as per your history.
If you are using some , do ask your doctor about it.
Make note of any triggers that appear to bring on your sweating such as a stressful event or eating certain foods.
You must avoid these items.
Increasing your vitamin intake can also help reduce head sweating. Taking a supplement or eating foods that contain a high level of B vitamins can help you manage your sweating more effectively. These include fruits, vegetables, whole grains and lean proteins such as eggs or fish.
Some foods can lead to a higher level of sweating. You should cut these foods from your diet to avoid head sweating. These include foods with a high spice level or foods with a great deal of garlic. You may also be able to balance out these effects by increasing your juice intake when you consume them.
Hope I have answered your query.
If any thing else you are welcome.
Good luck.

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