Blue nails may indicate an underlying condition. One blue nail often indicates a bruise under the nail (between the nail and the nail bed) as a result of a blow from a hammer or other hard object to the nail, a fingertip or toe becoming trapped, or stubbing the toe. or finger or due to a poorly fitting shoe or too long nails. The medical name for a blue nail due to a bruise is ‘subungual hematoma’. The bruise will grow out over time. It also happens that the nail loosens and falls off over time. If the blue nail hurts, your doctor can make a small hole in the nail to allow blood to drain and reduce the pressure between the nail and nail bed. There are also other possible causes of a blue nail, such as cyanosis and cold temperatures.
- Blue nail(s)
- Hematoma
- Cyanosis
- Cold temperatures
- Causes of blue nails
- Hemorrhage under the nail
- Lung diseases
- Heart disease
- Abnormal blood cells
- Cramps in the blood vessels
- What does a bruise under the nail look like?
- Blue to black nail discoloration
- Blue nail grows out or blue nail falls off
- What to do with blue nails?
- Trauma or accident
- Remove blue nail
Blue nail(s)
Hematoma
A blue nail or bruise under the nail is an accumulation of blood under the nail, between the nail and the nail bed. A blue nail is a result of direct trauma to the fingernail. The pressure created by this accumulation of blood under the nail can cause (severe) pain, but that is not always the case.
Cyanosis
Blue nails can also be caused by a lack of oxygen in the red blood cells. This condition is known as ‘cyanosis’. It occurs when there is not enough oxygen in your blood and the skin or membrane under the skin turns a purple-blue color.
Blue nails can also indicate a blood disorder called ‘methemoglobinemia’, where the body produces too much of a specific form of hemoglobin called ‘methemoglobin’. Due to the high levels of this type of hemoglobin, oxygen is not released properly into the body. This can also lead to cyanosis
Cold temperatures
Cold temperatures can cause your nails to turn blue. This is because cold temperatures constrict your blood vessels. The narrowed blood vessels make it difficult to transport the right amount of oxygen-rich blood to your nails. If the normal nail color returns when you warm or massage your hands, the blue color is likely the result of that part of your body not getting enough blood supply due to cold temperatures.
Blue fingers due to cold temperatures are a normal reaction of the body to keep the internal organs at the right temperature. However, if the nails remain blue, there may be an underlying disease or structural abnormality.
Causes of blue nails
Hemorrhage under the nail
A blue nail is caused by bleeding from the nail bed. There can be many causes that can cause a blue nail:
Runners can make quick braking movements in the shoes / Source: Istock.com/logoff
- a blow from a hammer or other hard object on the nail;
- a fingertip or toe becoming trapped, for example between a (car) door;
- hitting the toe or finger hard;
- rapid braking movements in the shoes, which mainly occurs in runners, joggers, tennis players, basketball players and squash players;
- ill-fitting shoes;
- too long nails.
In the case of a bruise under the nail, there must always be an event or incident that corresponds to it (bumps, sports, other trauma). If it is absent, it is difficult to distinguish from subungual melanoma (skin cancer under a toenail or fingernail – melanoma is an aggressive form of skin cancer). Blue discoloration of your nails can be caused by problems in the lungs, heart, blood cells or blood vessels. A list of conditions that can cause cyanosis include:
Lung diseases
- COPD (emphysema or chronic bronchitis);
- Asthma;
- Respiratory failure (breathing failure), breathing in which the lungs do not work sufficiently;
- Pneumonia;
- Pulmonary embolism (or pulmonary embolism).
Heart disease
- Congenital heart disease (abnormal structure of the heart and blood vessels) in children;
- Eisenmenger’s syndrome;
- Congestive heart failure.
Cold, numb, painful fingers and/or toes with Raynaud’s phenomenon / Source: WaltFletcher, Wikimedia Commons (CC BY-SA-4.0)
Abnormal blood cells
- Methemoglobinemia, a disorder of the blood or red blood cells that causes you to absorb too little oxygen;
- Carbon monoxide poisoning
- Polycythemia vera (PV), a rare disease of the bone marrow.
Cramps in the blood vessels
Raynaud’s Phenomenon: this condition refers to the sudden appearance of discoloration of fingers and/or toes when exposed to cold or during emotion, as a result of spasm in the blood vessels that temporarily reduces blood flow to fingers and/or toes.
What does a bruise under the nail look like?
Blue to black nail discoloration
The bruise under the nail often looks like a blue or red-black discoloration. A blue nail can be accompanied by pain, which is the result of accumulation of blood causing increased pressure on the nail bed. The pain usually only occurs several hours after the incident, when the pressure has increased. A blue nail does not necessarily have to cause pain.
Blue nail grows out or blue nail falls off
A bruise under the nail normally grows out. This can take up to six months. However, the blue nail can also peel off after a while and then fall off, after which it is replaced by a new one.
Paracetamol has an analgesic effect / Source: Martin Sulman
What to do with blue nails?
The treatment of blue nails depends on the cause and is aimed at restoring the oxygen level in the blood. In the event of a bruise due to injury or trauma, first aid is required.
Trauma or accident
After the incident, cool the finger or toe under a cold tap and keep the affected body part elevated. You can also cool with ice or a cold pack, but you must place a cloth in between to prevent frostbite. Do not refrigerate for more than about 5 minutes. If the bruise under the nail is small and does not hurt, it does not need to be treated. If the blue nail hurts or starts to throb, you should contact your doctor. The pain is caused by an increase in pressure under the nail bed. The doctor can possibly make a hole in the nail with a drill or disposable needle, allowing the unclotted blood to drain, relieving the pressure. However, clotted blood under the nail is not so easy to remove.
Remove blue nail
Large bruises that cause many complaints sometimes have to be treated by removing the nail. An infection can be prevented by placing the hand or foot in question in a bath with clean water with a very small amount of washing powder (not soda) every day after the treatment. Any after-pain can be counteracted with paracetamol.
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