Excessive sweating, known as hyperhydrosis, is a common condition.
It's normal to sweat when it's hot or you are under stress or during excercise, but for some, sweating occurs all the time.
There are many treatment options for excessive underarm sweating. If regular antiperspirants aren't working, try one that has aluminum chloride which can be found over the counter.
If that doesn't work, there are other options which include medications, botox and microwave/laser treatments to destroy the sweat glands.Talk to your doctor to discuss which options would be best for you.