As with all human conditions, there is a wide range of "normal" with some people hardly sweating at all, whilst others sweat to a much larger extent.

Most normal or heavy sweating can be controlled with shop bought anti-perspirants or aluminium chloride. When the amount of sweating is excessive and cannot be controlled by these measures it is termed "hyperhidrosis". 

Although some people have hyperhidrosis as a consequence of another illness, in many others it is merely due to overactive sweat glands or overactivity of the sympathetic nervous system.