When you get a blood test, it's possible that you could be left with a bruise. Learn how it can happen, and what to do if it does. If your doctor orders a blood sample, your blood will be collected by either a doctor, nurse, or phlebotomist. That's someone who's specially trained to collect
blood samples. First, the person taking your blood will place a tourniquet around your arm above where your elbow sits. This helps your veins become easier to see and work with. Then they'll clean and disinfect the area on the inside of your elbow. After that, a small needle gets placed into your arm. Once the needle is in your arm, samples of your blood will be collected in small vials or
bottles. Next, they will take the needle out of your arm and apply pressure with a gauze or a cotton ball over the spot where the needle was inserted. They'll ask you to keep applying pressure until the area stops bleeding, and then they will put a clean bandage over it. Getting blood drawn is a simple process, but the most common complication associated with it is
bruising. Your doctor might call this kind of bruise is also called a hematoma. That's a swollen area filled with blood. A hematoma that you get after a blood test often looks more serious than it is. Over the following days, the blood inside the hematoma will absorb back into your body. The blood that surfaces closest to the skin is what causes its purple appearance. As the days pass, the
bruise will fade in color, turning yellow or green until it eventually disappears. To help your bruise heal properly, you can: You should seek medical attention if:How Blood is Drawn
If You Get a Bruise
When to Call Your Doctor
What is a bruise or a hematoma?
Although bruises and hematomas may present similarly, they are different conditions.
A bruise, also known as a contusion, typically appears on the skin after trauma such as a blow to the body. It occurs when the small veins and capillaries under the skin break.
A hematoma is a collection (or pooling) of blood outside the blood vessel. Hematomas are classified as subdural, spinal, subungual (under the finder or toenail bed) or hepatic (liver).
Causes of bruise or hematoma
Causes of a bruise
- Accidents or bumps
- Microscopic tears in the blood vessels under the skin in athletic people
- Bleeding disorders — unexplained bleeding that occurs without reason
- Thinner skin due to aging
Causes of a hematoma
Trauma is the primary cause of a hematoma. Trauma can be the result of a car accident, fall, broken bones, gunshot wound or head injury.
Hematomas may also be caused by:
- Aneurysm
- Certain medications
- Viral infections such as rubella, mumps, chickenpox, HIV or hepatitis C
- Orthopedic injuries such as fractures
Risk factors for bruise or hematoma
Risk factors for a bruise
People who have any of the following factors are at higher risk for developing a bruise.
- Vitamin C deficiency
- Bleeding disorders
- Patients who take anticoagulants (blood thinners)
Risk factors for a hematoma
- Older age
- Anticoagulant (blood thinner) usage
- Recent trauma
Symptoms of bruise or hematoma
Symptoms of a bruise
- Dark blue or purple patch of skin that appears within a few hours after injury
- Tenderness on or around the affected area
Symptoms of a hematoma
- Inflammation
- Redness
- Tenderness
- Warmth
- Pain
- Swelling
Diagnosis of bruise or hematoma
Diagnosing a bruise
Most people can self-diagnose a mild bruise after evaluating the signs or symptoms.
If you have a severe bruise and suspect you may have more serious injuries, your doctor may order an x-ray of the area to ensure you do not have broken bones.
If you have frequent bruising, your primary care doctor may order a blood test to check for a bleeding disorder.
Diagnosing a hematoma
If the hematoma symptoms are severe or if it continues to expand over the course of a few days, you should visit your doctor right away. Emergency medicine, urgent care, primary care physicians frequently care for patients with hematomas.
A primary care doctor can diagnose a soft tissue hematoma in a physical exam. If you are experiencing more serious symptoms, your doctor may order any of the following diagnostic tests:
- X-ray — to diagnose bone fractures
- CT scan — to diagnose head injuries
- Ultrasound — for pregnant patients
Treatment for a bruise or a hematoma
Treatment should begin as quickly as possible after injury. First-line therapy is rest, ice, compression and elevation (RICE method). If the injured area is painful, the injury can be treated with OTC medications like Tylenol or Advil.
If you have a hematoma that involves other organs in the body, your treatment will be tailored to your situation.