Tobacco? Money? Oil?
I will assume
heroin. There are a number of possibilities and would need a simple exam to determine which one.
Muscle pull. Most common. Minor. Pressing the muscle on the outside gives the pain.
Pneumonia from infection. Serious. Usually with cough, fever,
chills, gunk coming up.
Irritated lung like a pneumonia but not infection. Cough, often wheeze. Can be from the stuff in the heroin (minerals like talc go into the lung, but cannot come back out again). Can seriously rot the lung.
Pneumonia from HIV. Can be very subtle with little or no fever, but cough, wheeze, breathlessness and feeling very unhealthy. BUT, snorting is a zero risk of it. Has to be exposure to LIVING infected CELLS (sharing needles, sexual transmission).
Allergic reaction (wheeze, feeling like terrible
asthma attack... unlikely).
Blood clot (can be very few symptoms. would almost be coincidental , unlikely).