點解晚晚訓著左冇幾耐就會成身出哂汗既???

There are some possibilities:

1. hormonal problem 荷爾蒙失衡 - Hormone production is controlled by the brain. If there is a tumour inside the brain, like pituitary (腦垂體) tumour. The control of sweating is concerned.

2. near menopause 更年期, your symptoms are most likely to be menopause if you are around 50 years old lady. Please see http://www.hk-doctor.com/health_article/dept_health/DH75.htm
Those information are useful.

3. stress 壓力;緊張;

Please find a good doctor to check up. Doctor will do some blood test or scan for you. Don't worry, it is not a big problem. See doctor earlier.
I hope the above information is helpful to you.