The medical term for excessive sweating is hyperhidrosis.
Excessive Sweating is split in to 2 distinct groups Primary Hyperhidrosis and Secondary Hyperhidrosis
It is not known why Primary Hyperhidrosis occurs but it is excessive sweating from eccrine sweat glands that are located on palms of hands, soles of feet, face and armpits.
There are a number of specialist antiperspirants but if they do not work, the recommended option is treatment with a botulinum toxin.
This is much more generalised – over the whole body and often at night.
There are a number of causes of generalised excessive sweating but if it is something you have had it for some years and happens occasionally with no other symptoms and then it is likely to not have an underlying medical cause. If of recent onset and persistent or accompanied by feeling unwell or weight loss it requires investigation by your doctor.
Some causes are: