Welcome to HCM!
I have gone through your question carefully and after giving it adequte consederation and from all the information you have given here, I feel that you should go and meet a cardiologist at least once.
The brownish saliva and chest tightness
, abdominal cramping can all take place in soem cardiac cause. Moreover, any respiratory tract
problem which may be causing these are almost ruled out coz you have no cough, cold /flu....
Had I been your doctor, I would definitely do an ECG, Chest X ray, ECHO, along with routine blood test
. An ultra sound
abdomen can tell if there is any other abdominal problem.
Till you meet doctor please avoid sternous activities/ quit smoking
and drinking alcohol completely (if you use them).
You have not mentioned your age and if you have any other disease, so, at present I cannot relate your presentation to anyhing more.
Hope this answer helps you in successfully dealing with this problem.
Feel free to ask more queries if you need.
Dr. Manisha Gopal.