What is a blood blister?
A blood blister is a raised piece of skin that has blood inside it. Blood blisters are somewhat similar to blisters that have clear fluid in them. The blisters are usually harmless and tend to go away within a few weeks without treatment. A blood blister can contain blood, lymph fluids, or other body fluids, which are trapped beneath the skin.
These reddish to purplish fluid-filled bumps are extremely painful even when slightly touched. Hence, if they get punctured, they can ooze out a dark fluid. The fluid can be cut off from the body and then dries up. Once it dries up, it leaves a dead cell material inside the blister, which has a texture similar to a paste or putty.
There is nothing to worry about when you see a blister filled with blood. Blood blisters are quite common and are usually caused by skin injuries. It usually heals all by itself but would take days or weeks to completely recover.
Causes of blood blisters
Blood blisters are caused by high-pressure injuries. The depth of the injury can go down to the small blood vessels in the dermis.
The blood then flows to the epidermis and mixes with the blister's fluid, creating a blood blister. The blisters usually occur over the joints or areas where there are prominent bony structures such as the back of the heel, heels, toes, and at times, at the ball of the foot. Below are some of the reasons why you get blood blisters:
- Something pinches your skin but doesn’t break the skin open
- Wearing ill-fitting shoes
- Hands or fingers that get caught in a door jamb
- Intensive sunburns
- Skin reactions due to allergens such as chemicals and other irritants
- Herpes or warts caused by HPV
- Tinea pedis - a fungal infection of the feet that mostly occurs between the toes or on the soles of the feet
- Searing burns
- Using tools that constantly rub against the skin such as a hammer
- Sweaty feet that can cause additional constant friction against the foot and the shoe
- Engaging in sports or any type of physical activity that requires constant standing for longer durations such as running and dancing.
As mentioned earlier, blood blisters are quite similar to friction blisters. Friction blisters are the ones that are generally filled with a clear fluid. Blood blisters can vary in size and they appear as a pocket of raised skin. The blister can be red to purplish or black in color. New blood blisters initially appear as red and then gradually turn into a much deeper shade such as purple or black.
Blood blisters can form on any part of the body. However, they are often formed in areas that are under constant pressure. Blood blisters can be formed in the mouth, hands, feet, near the joints, or around any bony areas of the body such as toes, heels, or ball of the foot.
When to visit a doctor
Having a single blood blister is usually not a cause for worry. However, you need to consult a doctor if you have the following:
- Multiple blisters on the skin with unknown reasons
- Blood blisters in your mouth or on the eyelid
- Warmth or red lines leading away from the blister
- Blisters that appear for no reason
- Signs of an allergic reaction
- Burn injury
- Recurring blisters even after treatment
In most cases, blood blisters are left alone to heal all by themselves. The blisters usually take 1-2 weeks to heal without any treatment. The healing process involves the formation of the new skin underneath the layer of the raised blister. Over a period of a few days or weeks, the blood in the blister gradually dries out without any treatment.
However, extra care should be taken to protect the blood blister during its healing period. To protect the affected area, you may want to wrap it with a protective layer such as a bandage. If the blood blister hurts, you can apply an ice pack or ice wrapped in a towel. You can also take medications such as ibuprofen (Advil) or acetaminophen (Tylenol) for pain relief. However, seek medical help if the blisters become unbearably painful.
1) Get the pressure off
Try to remove or reduce the pressure on the affected area to let the blister roof remain intact, allowing it to heal on its own. People who have blisters on top of their toes can wear open-toed sandals instead of closed shoes. If you take away all pressure from the blister, it would remain intact with fewer chances of infection. If the blood blister happens to be in the weight-bearing area of your foot, then the situation won’t be as simple as it seems.
2) Cut friction levels and reduce pressure
If the blood blister occurs on the ball of the foot, then reducing the pressure off the foot won't possibly work. The only option would be to just keep going on. However, you can use a thick adhesive orthopedic felt, which can be cut in the shape of donut pads. Place the cavity on the blister so that the pressure is taken off.
Natural home remedies
1) Ice compress
Try applying a pack of ice or ice compress on the affected skin area. The ice pack should be applied on the injury for around 10-30 minutes. The cold temperature of the ice will allow the constriction of blood vessels, thereby decreasing the swelling on the affected area and preventing any internal bleeding. You can apply an ice pack or give cold compresses multiple times after an injury. However, do not directly place the ice on the skin to avoid an ice burn. Applying ice is one of the best remedies to remove blood blisters caused by burns.
2) Aloe vera gel
Aloe vera gel from a fresh aloe vera plant contains anti-inflammatory properties that can naturally treat blood blisters. Aloe vera contains naturally occurring phenolic compounds, which are also called anthraquinones. They would help the blood flush out unnecessary waste materials from the blood blister. To extract the gel from the plant, simply break open an aloe vera leaf. Get the fresh gel and apply it directly on the blister. Apply the gel 4-5 times a day until the blister heals.
3) Turmeric powder
Turmeric powder contains curcumin, which is a potent phytonutrient with anti-inflammatory properties. Turmeric is known to heal blood blisters naturally. It also contains antiseptic properties that help prevent possible infections. One can easily make a paste out of turmeric powder. Apply the paste directly on the affected area. Turmeric is also known to heal other skin problems such as burns or any other blisters.
4) Cucumber juice
Cucumber is also another known remedy to heal blood blisters. Cucumber contains many nutrients, which are beneficial for the skin. Nutrients include vitamin B1, C, and K. Cucumber also contains silica, which is known to strengthen the connectives tissues of the skin. Cucumber slices can be applied around the blood blister or drink at least two glasses of cucumber juice on a daily basis to keep the body cool.
Blood blisters can take months or more to completely disappear. It takes somewhere from 30-48 days for full epidermal turnover of the cells. Thus, it would take a longer time for the traces of the blister to disappear. The blood in the blister can dry very quickly. If an individual cannot identify the exact cause of the blister, then healing can take a bit longer.