What can be done to reduce bad cholesterol ldl only, not increase the good cholesterol hdl?

LDL and HDL: In general high LDL cholesterol is associated w/ higher risk of heart & artery disease, while high HDL is generally protective. Genetics is a major determinant of what your levels will be; diet has some influence. Treatments include diet, exercise, & drugs including statins, fibrates, binding resins, & recently some fancy biologic drugs. Medical guidelines on who/how to treat are now very detailed