What harm does smoking do to fitness?

Lead to respiratory diseases and eventually lead to lung cancer.

Cause memory loss

Lead to decreased sexual ability

Resulting in decreased sperm survival rate.

Causes chapped skin.

The decline in fertility quality affects the healthy growth of the next generation.

Causes blood to thicken and cause drowsiness.

It causes relatives and friends who don't smoke around to passively absorb second-hand smoke, which affects their health.

pollute the environment

That's all I can think of for the time being.