Title: Blood Testing Guide | Drugs.com
Headings: Blood Testing
Blood Testing
What is Blood Testing?
What It's Used For
Preparation
How It's Done
Follow-Up
Risks
When to Call a Professional
Further information

Content: You may experience slight pain or a pinching or stinging sensation when the needle pierces the skin and enters the vein. Some people get a throbbing in the arm caused by the tight elastic band used to engorge the veins. A little blood often seeps out of the vein where the needle was inserted, causing bruising under the skin. Bruising in the area may appear on the day following your blood test. There is no need to be concerned unless it is painful or the bruise continues to enlarge. Your body will reabsorb the blood that seeped out. As with any procedure that breaks the skin, there is an extremely low risk of infection. Tell your doctor if the area becomes red, hot to the touch, painful, or if you develop a fever with these symptoms. Some people feel faint or lightheaded, especially when a larger amount of blood is taken. When to Call a Professional
Because harmful side effects are not expected, people typically need to call their doctors only to discuss laboratory results.