Blood blisters are caused by skin trauma, such as forcible pinching. The result is a red, fluid-filled bump that can be very painful to the touch. While most blood blisters are not serious and will eventually go away on their own, it is important to learn how to treat a blood blister to minimize discomfort and prevent infection. There are a number of steps you can take at home in blood blister treatment to ensure the blister heals in its entirety.
Treating it Immediately after Injury
- Remove pressure from the blood blister. Start by eliminating any pressure and exposing the blister to the air. You want to make sure nothing rubs against it, or presses down on it. Exposing it to the air allows it to start healing naturally. If it is not under any pressure, it will stay intact and the chances of it tearing or bursting and becoming infected are lessened.
- Apply ice to the blister if it is painful immediately after the injury. Ice packs can be applied to the area for 10 to 30 minutes at a time. You can do this to reduce the pain and cool it if it is warm and throbbing. Icing the blister can be done regularly too, not just immediately after the injury.
- Under normal circumstances, do not pop the blood blister. It may be enticing, but popping the blister could lead to infection and delay the body’s natural healing process. If the blood blister is on the foot, try not to put extended pressure on it.
Allowing it to Heal on Its Own
- Keep it exposed to the air. Most blood blisters will heal on their own over time, but keeping the area clean and dry will allow the healing process to go as quickly as possible. Keeping it exposed to the air helps the healing process, but also limits the chances of infection.
- Reduce any friction or pressure. If your blood blister is in an area that would normally be rubbing up against something, such as your heel or toe, take precautions to limit the friction against the blister. It is more likely to tear or burst if it is subject to a lot friction, which is caused when it rubs up against another surface, such as your shoe. Using a plaster is the most straight-forward way to do this.
- You can get certain donut-shaped plasters than reduce the friction while still leaving the blister exposed so it heals more quickly.
- Protect it with a bandage. Blisters that rub against something regularly, such as those on the feet or fingers, can be covered with a loose bandage for additional protection. Bandages lower the pressure on the blister and reduce the friction, the two key things in helping a blood blister heal and lowering the chances of infection. Be sure to use a sterile dressing, and change it regularly.
- Before applying a dressing clean the blister and surrounding area.
- Continue your blood blister treatment until the area heals completely. If the blister is extraordinarily large, make an appointment with your doctor. These blisters do sometimes need to be drained, and it is best to do so under professional supervision to prevent infection.
Knowing How and When to Drain a Blood Blister
- Decide if it is best to drain the blood blister. Although blood blisters will heal on their own, and should be left to do this in most cases, there are times when draining them might be the best option. For example, if it is collecting a lot of blood and causing a lot of pain. Or if it is getting so big it is likely to tear anyway. Think about if you really need to drain it, and err on the side of caution.
- This is especially the case with blood blisters, which require more careful treatment than normal blisters.
- If you do decide to drain it, you have to careful and methodological in order to limit the chances of infection.
- Due to the risk of infection, you should never drain a blood blister if you have a condition such as HIV, heart disease or cancer.
- Prepare to lance the blood blister. If you have decided that you need to drain the blood blister you need to ensure you do not infect it. Wash your hands, and the area where the blister is, thoroughly with soap and water before you begin. Next sterilize a needle with rubbing alcohol. You are going to use this needle to lance the blister. (Never use a straight pin – they are less sharp than a needle, and sometimes have bur on the end.) 
- Lance and drain the blood blister. Carefully and gently puncture the edge of the blister with the needle. The fluid will begin to drain out of the hole you have made. You can apply very gentle pressure to help it on its way if necessary.
- Clean up and dress the drained blood blister. Now apply an antiseptic (assuming you have no allergies) such as betadine, to the blister. Clean around the blister and dress it with a sterile dressing. Once you have done this you should avoid pressure or friction on the blister as much as possible. To ward off potential infection you should observe it closely and regularly change the dressing.
Treating a Burst or Broken Blood Blister
- Drain it carefully. If the blister bursts or tears as a result of pressure or friction you need to act quickly to clean it up in order to prevent infection. Begin by carefully draining the fluid from the blister if it has burst.
- Clean it and apply an antiseptic. Washing the area thoroughly should be followed by the application of an antiseptic ointment (allergies permitting), just like if you had drained the blister yourself. Avoid using alcohol or iodine directly on the blister, because these substances could delay the healing process.
- Leave the skin intact. After draining the fluid take care to leave the extra skin intact, carefully smoothing it over the raw area of skin. This provides additional protection for the blister and facilitates the healing process. Don’t pick away at the skin around the edges of the blister.
- Dress it with a clean bandage. Applying a clean bandage to the blister is very important in the prevention of infections. The bandage should provide sufficient pressure to avoid further blood vessel ruptures, but should not be so tight that it impedes circulation to the area. Change the bandage daily after cleaning the area. You should allow your blister around a week to heal.
Monitoring for Signs of Infection
- Watch carefully for signs of infection while caring for your blood blister. If the infection becomes severe, your doctor may prescribe oral antibiotics to treat the infection completely. It is important to clean and dress the blister well in order to lessen the chances of suffering an infection.
- If you begin to feel generally unwell with a fever or high temperature this could be an indicator of an infection.
- Look for increased pain, swelling or redness around the blister. Signs of an infection include redness and swelling around the site, or soreness that develops long after the blister occurs. Keep a close eye on the blister for these symptoms and take appropriate measures.
- Look for red streaks extending from the blister. If you can see red streaks moving away from your blister this could be an indicator of a serious infection that has spread to the lymph system. Lymphangitis often occurs when the viruses and bacteria of an infected wound extend into the channels of the lymphatic system.
- Other symptoms of lymphangitis include swollen lymph nodes (glands), chills, fever, loss of appetite, and a general malaise.
- If you are experiencing these symptoms contact a doctor immediately.
- Look for drainage of pus and fluid from the blister. Pus discharge is another indicator of a potentially infected blood blister. Look out for yellow and green coloured pus or cloudy fluid gathering in the blister or draining out from it.