Keep Breathing...

From the moment you take your first breath until your last few moments alive on this earth, you must keep breathing...or it's all over. Many of our problems and illnesses are because you are not doing it right. Sure, more or less our breathing is automatic an unconscious event taking place as a normal function of our body. But as a science of yoga, particularly HathaYoga, conscious breathing or a degree of awareness of our breathing is an important part of Hatha.
Some of the specifics are or can be somewhat complex or in fact may be dangerous to your physical or mental health. So, these remarks are simply for general information on breathing and to give us view  expressed by the western medical profession, that is Occidental Doctors.

A form of deep breathing exercise  is recommended for those with chest and lung problems or recovering ex-smokers. Suggestion are:
Sit in a comfortable position in a chair.
Relax your back as much as possible, sitting up straight.
The feet should touch the floor. (Or you can sit cross legged in a yoga position).
Inhale through the nose ( not the mouth).
Exhale through the mouth, exhale with pursed lips.
Exhaling should be slower than inhaling.

Inhale:
When inhaling place both hands on your stomach, spread fingers out, concentrate
on expanding belly as you inhale through the nose.Slowly.

Exhale:
The exhale slowly through pursed lips. The exhale should be longer and slower
then the inhale.

Try to do this conscious breathing exercise 4 times a day or more.