Unexplained Bruising On Legs

What are Bruises?

A fall or bump may cause blood vessels to rupture under the skin which often leads to the development of bruises. It usually occurs because the blood from the vessels leaks into the tissues under the skin giving it the black and blue color which is characteristic of bruises. They may change color and become reddish blue, yellowish green or purplish-black as they gradually heal within 2 to 4 weeks. Sometimes the bruises spread in the direction of gravity, i.e., towards the lower half of the body. Thus, a bruise on the face or shoulder heals faster than a bruise on the leg. Bruises usually take a day or two to appear. However, if a person experiences swelling, bruising and pain within 30 minutes of the injury, then it may be indicative of a more serious problem.

Unexplained Bruising on the Legs

Bruising one’s legs while playing or due to an injury are quite common and is not considered to be a severe or life-threatening situation. However, if people frequently notice bruises on their legs and do not remember when the injury had taken place, it could be due to an underlying ailment. These bruises take a very long time to heal after they appear. Unexplained bruising is commonly a result of diseases that disrupt the circulation of blood in the body.

Unexplained bruises on legs

Causes Of Unexplained Bruising On Legs

  • Aging – Bruises known as actinic purpura are found at the back of the arms and hands in older people. It happens when blood vessels become weak due to repeated exposure to the sun. They first appear as flat red blotches and change color to purple, become deeper before they gradually fade away. The condition can worsen under the influence of alcohol, aspirin, Coumadin, etc.
  • Thrombophilia – Thrombotic thrombocytopenia purpura and idiopathic thrombocytopenia purpura are bleeding disorders that cause low platelet count. Further, it also affects the body’s normal ability to form blood clots increasing the chances of bruising.
  • Medication – Consumption of medications such as ibuprofen, warfarin, aspirin, corticosteroids, cortisol, Prozac, anti-inflammatories, and birth control pills make the blood thinner. These medicines disrupt circulation and increase chances of bruising. Some natural supplements like fish oil, garlic, ginkgo biloba, etc. also have the same effect. However, it is highly unlikely that natural supplements can cause the excessive thinning of blood unless they are used along with thinning blood medication.
  • Diabetes – Bruises on the skin are common in case of disruption in circulation. Diabetes is one such medical condition that causes problems in circulation, thus placing people with diabetes at a higher risk of developing bruises. Areas, where insulin is injected to treat diabetes may show hyperpigmentation. Brown or black patches also appear where the skin creases or folds. Increased bruising on the legs along with fatigue, excessive thirst, blurred vision and increased susceptibility to infections are symptoms that help in the diagnosis of diabetes.
  • Hemophilia – Such a condition induces an increase in the tendency to bleed. Hemophilia occurs due to an abnormality in blood clotting functions that prevent the formation of blood clots. Heavy bleeding and bruising are signs of this disease.
  • Injury – Excessive exercise or recent injury may lead to bruising due to damage or tear of blood vessels under the skin. Moreover, blood leakage may occur in the adjoining tissues. It might be one of the reasons behind the bruises.
  • Nutritional Deficiency – Deficiency in certain vitamins such as Vitamins K and C, minerals like zinc and iron and bioflavonoids like citrine, rutin, quercetin, and catechin are valuable in correcting tendency of frequent bruising. Deficiency of the elements mentioned above can lead to circulatory problems, resulting in unexplained bruising.
  • Cirrhosis – Cirrhosis is a condition that affects the liver where scarred tissues replace healthy tissues due to injury or disease. It disrupts the immune system function, protein production, blood health, etc. It causes unexplained bruising, excessive weight gain and lack of energy making people more susceptible to liver cancer.
  • Chemotherapy – Chemotherapy is a treatment for cancer that refers to the killing of cancer cells by the use of radiation. It could also result in low blood platelet count and underproduction of platelets. Further, this induces increased chances of bruising.
  • Graves’ Disease – It is an autoimmune disease that stimulates the thyroid gland to produce more hormones. The hormones increase the rate of metabolism causing excessive and quick weight loss which ends up damaging the blood vessels and capillaries under the skin. It can lead to bruising in the legs and other areas. Other side effects of this condition include irritability, light menstrual flow, difficulty in sleeping, irritability, physical weakness and rapid heartbeat.
  • Ehlers-Danlos Syndrome – Certain collagen disorders cause bruising, these disorders are inherited from one generation to the other, and Ehlers-Danlos syndrome is one such disorder. It refers to a condition in which the tissues surrounding the blood capillaries and vessels are weak and break easily. Features of this syndrome include delayed wound healing, rupture of hollow organs like the intestine and gravid uterus and rupture of arteries leading to excessive internal bleeding and premature death.


  • Bruise is reddish when it first appears and then changes color from blue to dark purple and then to yellow or green
  • Bruise is tender and painful for the first few days, but the pain subsides as the color fades
  • No risk of an infection as the skin is not broken in the form of a cut or scrape


  • X-rays
  • Blood test
  • Enquiry about the patient’s medical history
  • Examination for signs of physical abuse

Treatment For Unexplained Bruising On Legs

  • Medication – Limiting the use of medications like aspirin which increases the risk of bleeding and bruising by slowing the process of blood clotting helps to treat bruises. Also the use of anti-inflammatory drugs aids in lowering the swelling that accompanies the bruises.
  • Applying Cold Compress – The size and tenderness of the bruise can be limited by applying a cold compress. Placing a towel in between the skin and the cold compress is advisable because direct contact with ice can damage the skin. Application of the compress for 20-30 minutes on the bruised area is suggested.
  • Applying Warm Compress – Using a warm compress is helpful in case of an injury that persists for more than 2-3 days. Application of the warm compress for about 10 minutes, 2 – 3 times in a day reduces discomfort, increases blood flow in the bruised area and clears the damaged blood cells that may have accumulated under the skin.
  • Restricting Blood Flow – In case of injuries on the leg or arms, the limbs should be placed at an elevation above the heart while the person remains in a lying position. It helps to limit the flow of blood which subsequently controls the swelling. To yield the best results, a person should maintain this position within the first 24 hours of the appearance of the bruise.

When to Visit a Doctor?

Medical help must be taken from a doctor in case of the following situations:

  • Swelling and pain accompanies bruise
  • Easy bruising without being able to recall any proper reason or injury
  • Painful bruise under toenail or fingernail
  • Bruise does not improve within two weeks or heal completely within 3-4 weeks
  • Bruise occurs above the eye and then travels to the area below the eye, causing black eye
  • If the person has a concussion

One Response

  1. janet lightner December 29, 2019

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