I have an lp(a) level of 135 nmol/l, and the rest of my lipid profile tests are all normal. i am a 21 years old, and 10 months post stem cell transplant. and i wanted to know if a high lp(a) level is dangerous and/or indicates heart disease?

Heart disease from abnormal cholesterol pattern is complex and not as simplistic as calling LP(a) dangerous though association has be found with high levels and risk of heart attack and stroke. If there is no family pattern of premature heart attack and stroke you probably should not worry about the LP(a). You were vague about normal for the lipid profile but that reiterates no need for concern.

The level itself does not indicate the presence of heart disease, but there is increased risk in the future. LP(a) cannot be reduced by any drugs, but it would be important to pursue all therapies that reduce risk of heart disease including healthy diet & exercise. If you have a family history of heart disease, then regular followup with a physician every few years is a good idea.