Bleeding and bruising
What is bleeding?
Bleeding, also called haemorrhage, is the term used to describe blood escaping from the blood vessels. Bleeding from the skin occurs if there is an injury to the skin surface, or may sometimes occur spontaneously. Smaller areas of bleeding are known as petechiae (each spot is less than 2 mm) and purpura (2 mm to 1 cm).
Subungual haemorrhage, or bleeding under a nail plate, results in painful or unnoticed purple-black discolouration. The discolouration may persist for months as the nail carries the blood with it as it grows out.
Examples of bleeding skin lesions
What is bruising?
A bruise, also known as an ecchymosis or a contusion, occurs when small blood vessels (capillaries) under the skin bleed, while the overlying skin remains intact. The injury causes blood to leak and collect near the skin surface, causing a bluish-black skin discolouration.
Deeper bruising results in a haematoma – a collection of blood that lies within body tissues or cavities.
Anyone can bleed from a cut or develop a bruise after an injury. The severity of bleeding depends on the impact of an injury. Repeated bleeding from a skin lesion with minimal provocation can be a sign of a skin cancer, most often basal cell carcinoma.
Occasional bruises are normal, and do not warrant medical attention. Bleeding and bruises are more common in certain individuals, such as:
- People with lighter skin tones, where bruises are more visible
- People who exercise a lot or who play contact sports
- Older people, as the walls of their blood vessels weaken and their skin becomes thinner
People with an inherited or acquired coagulation disorder.
Bruising occurs more readily in certain sites where blood accumulates easily, such as when a relatively minor bump results in a black eye.
What causes bleeding and bruising?
After injury, the body immediately attempts to stop any blood loss.
- Platelets accumulate and block any defects in the blood vessel walls.
- Blood vessels constrict.
- Clotting factors are released.
Defects in any of these three responses can lead to spontaneous or excessive bleeding and bruising.
Platelets can be dysfunctional or decreased in number. This can be due to conditions such as:
- Aplastic anaemia
- Autoimmune disorders such as systemic lupus erythematosus
- Disseminated intravascular coagulation
- Haemolytic uraemic syndrome
- Thrombotic thrombocytopenic purpura
- Kidney disease
- Drugs that affect platelets, eg, aspirin and clopidogrel prescribed to prevent heart attacks and strokes, and non-steroidal anti-inflammatory drugs.
Blood vessel defects include:
Clotting factor deficiency may be due to drugs that affect clotting factors, eg, warfarin, heparin, rivaroxaban and apixaban. These are often prescribed for atrial fibrillation or a recent blood clot in veins or lungs. A clotting factor deficiency can also be a result of a medical condition, such as:
- Liver disease
- Vitamin K deficiency
- Von Willebrand disease
- Deficiencies in other clotting factors.
Signs of bleeding disorders
What are the symptoms of bleeding and bruises?
Larger blood vessels such as arteries lead to more profuse and prolonged bleeding than smaller ones such as capillaries. Once bleeding has stopped, a blackish crust or scab forms while the wound heals underneath.
Typically, a bruise first appears as a reddish patch, which develops over a few hours into a blue, black or purple discolouration. It may feel tender immediately after bruising, and the area may be swollen. Over a few days, the colour fades to a yellow-green, as the extravasated blood breaks down.
What tests may be performed?
Usually, tests are not required for bruises. However, if a broken bone is suspected, an X-ray may be required.
If bruises are occurring for no reason or extremely frequently, blood tests may be required to confirm a coagulation defect and determine if there is an underlying medical problem.
- Petechiae may be due to a platelet defect.
- Pigmented purpura may indicate capillaritis.
- Palpable purpura suggests vasculitis.
- Large bruises suggest coagulation factor deficiencies from liver disease or von Willebrand disease.
- Bleeding into the joints may indicate haemophilia.
- Ooze around catheters and blood-letting sites in a sick patient could indicate disseminated intravascular coagulation, vitamin K deficiency, or thrombocytopenia.
When should I seek medical care?
Urgent medical care is required if the bruising is associated with swelling and extreme pain, as it could indicate a fracture in the underlying bone.
Medical assessment is also indicated for:
- Bruising that is more frequent or severe than normal
- Bruising for no reason
- Bleeding from the gums, from the bowel or in urine.
- Significant bruising or bleeding when on blood thinning medications
- Painful bruising under fingernails.
What is the treatment for bruises?
There is no particular medical treatment for bruises. There are some techniques that can be used at home to reduce swelling and speed up the process of healing.
- Prepare an ice pack wrapped in a towel or a cold flannel. Apply this to the affected area for 30 minutes, as soon as possible after the injury.
- If practical, keep the bruised area elevated after the injury.
Paracetamol may help with severe pain. Non-steroidal anti-inflammatory drugs, such as aspirin and ibuprofen, are not recommended, as they may worsen the bleeding leading to the bruise.
What is the outcome for bruises?
Bruises usually take around two weeks to disappear. They may take longer to disappear from the lower legs.
How can I prevent bruises?
- Wear protective clothing and equipment such as shin pads when playing sports.
- Keep furniture and other large objects away from walkways.
- Avoid obstacles such as wires that may lead to tripping.
- If you are taking blood-thinning medication, have monitoring blood tests and appointments.
- Ensure your diet has adequate vitamin C, found in fresh fruit and vegetables.