I just had a blood test, they say my fat count is hight, why is that bad?

Thy made me go on a low fat diet.
Lipids (several different types of fat as listed below) are found in your blood and are stored in tissues. They are an important part of cells, and they help keep your body working normally. Lipid disorders, however, such as high cholesterol, may lead to life-threatening illnesses, such as coronary artery disease (CAD), heart attack, or stroke.

Cholesterol: Too much cholesterol in the blood can build up along the inside of the artery walls, forming what is known as plaque. Large amounts of plaque increase your chances of having a heart attack or stroke.

Low-density lipoprotein (LDL): It is sometimes called "bad cholesterol." A high LDL cholesterol level may increase your chances of developing heart disease.

Very low-density lipoprotein: A high VLDL cholesterol level can cause the buildup of cholesterol in your arteries and increases your risk of heart disease and stroke.

Triglycerides: Having a high triglyceride level along with a high LDL cholesterol may increase your chances of having heart disease more than having only a high LDL cholesterol level.

Overall, there are recommended levels and probably your doctor is trying to get you down to these normal levels. That's why it's good you had the tests done and you have the chance to change your diet now and prevent some of those complications. From personal experience I can tell you that it's not that difficult to lower your levels if you are consistent at each meal and follow the advice given to you at the doctor's. Also, eating high-fiber foods (oats for example) provides a special boost in fighting high fats.

Good luck.
High fat content in your blood gives you high blood pressure, which makes your heart work too hard. It can lead to a heart attack without a change (that has already been made.)
you'll get diabetes! ahh! if you get it, u'll die. ur body cant hold up that much fat. or, its something else that isn't that bad. to lose weight, exercise 4 5hours!!!
Because to much fat in your blood can lead to clogged arteries and that in turn can lead to heart attacks and/or stroke