The general term used to describe elevated levels of cholesterol and other fatty substances in the blood is

Hyperlipidemia

Explanation:

The high cholesterol also refers to as Hyperlipidemia. The increase in level of fatty substances, cholesterol and triglycerides in blood is called hyperlipidemia. There are two types of lipoproteins that are HDL (high density lipoprotein) and LDL (low density lipoprotein). The excess HDL reaches liver and thus excreted. So, HDL is good for body but LDL is bad fat. The increased LDL in body causes hyperlipidemia. The increase LDL can lead to heart attack.

Thus, the general term used to describe elevated levels of cholesterol and other fatty substances in the blood is Hyperlipidemia.