Has any one been diagnosed with asthma and been discharged ?

I was diagnosed with Asthma after 20 years of service (15 active) after I had pneumonia. I did plenty of research on it at the time but I don't recall much of it now. With treatment I have no restrictions.

Find the appropriate regulation on medical chapters and find out the criteria to be retained in service or discharged and see how your charts match those marks.

Good Luck

Your provider will decide if you should be discharged or not. I developed asthma at 19, one month before going to Ranger School. I can't run as fast as I used to, but with training you can push fast enough to pass. Everyone gets weaker when they get older. This crap about not serving with as much distinction is a cop out. You just have to work harder for once in your life. The Army is supposed to teach you not to quit, not that you should quit as soon as it's no longer easy for you.
You won't get any help from your unit because this is a personal responsibility. Whether you are in the Army or out, your employer will not be responsible for helping you. Simply put, if your medical conditions prevent you from performing a job, you will be released from that job. That's in the Army and the civilian sector.
As for the medical separation, if you become unable to perform your job due to the asthma, you will be separated. Most providers won't even write asthma as a diagnosis in order to allow you to continue to serve. There are thousands of people in the Army with asthma who are serving with distinction. If you think serving with distinction means running fast, you are very mistaken. Get into those TMs and regs and pass your knowledge onto the junior Soldiers - that is serving with distinction.

I had a soldier who eventually got medically chaptered out for it.

It is a long process that requires a multitude of steps to form a conclusive diagnosis to include breathing treatments and other tests. it takes a while and usually gets sent to a MEB