Ldl Test

LDL test is done to monitor the risk of heart diseases, stroke or any other medical conditions that involve the blood vessels[arteries] like peripheral arterial diseases. In known cases of high cholesterol or LDL levels, the test is done to monitor the effectiveness of treatment and medications. How often the test should be done will depend on age, sex and risk of heart diseases.

The LDL test measures the level of low density lipoproteins(LDL) also known as "bad cholesterol" in the blood. I

The blood sample is taken from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a  little sting when the needle goes in or out. This usually takes less than five minutes.

Individuals with high cholesterol levels are often asymptomatic. However, high LDL levels may lead to hardening or thickening of the blood vessels leading to risk of heart diseases, strokes and other medical conditions involving the blood vessels. There are age and gender specific guidelines to decide if the high LDL levels require treatment or not. 
High LDL levels may also be sign of type 2 diabetes or prediabetes, hypothyroidism, certain genetic conditions, or side-effects of medications. Low LDL levels may occur due to lipoprotein deficiencies, hyperthyroidism, infections, inflammation or cirrhosis.