Chronic heroin users may develop collapsed veins, heart lining and valve infections, abscesses, cellulitis, and liver disease. Pulmonary complications, including various types of pneumonia, may result from the poor health condition of the abuser, as well as from heroin's effects on respiration.
In addition to the effects of the drug itself, heroin may have additives that do not readily dissolve. Absorbing these substances can cause the blood vessels that lead to the lungs, liver, kidneys, or brain to become clogged. Eventually, this may cause infection or even the death of small patches of cells in vital organs.