March is upon us and spring is looming (yippee!) but March also marks Deep Vein Thrombosis Awareness Month, commonly shortened to DVT. This is a national movement that seeks to educate people on what deep vein thrombosis is, what the symptoms are and the potential fatal complication: pulmonary embolism.
What Is A DVT?
There are deep veins and superficial veins in the body. A DVT is where a thrombus (blood clot) forms inside one of the deep veins, which are surrounded by muscle, blocking it either partially or completely. This usually occurs in the calf, but can also occur in other places in the body such as the pelvis or abdomen.
What Are The Signs and Symptoms?
A DVT can occur in any part of either leg, usually only in one leg (although this is not always the case) and symptoms can vary from mild to severe with some people not displaying any symptoms at all.
Symptoms can include:
- Pain and swelling in the leg
- Warm skin in the area of the clot
- Redness, particularly at the back of the leg below the knee
- Tenderness along the line of the affected vein
- Deep, heavy ache of the affect leg
These symptoms can also be an indication of other medical conditions and musculoskeletal injuries so if you experience any of the following your should contact you GP as soon as possible.
What Causes a DVT?
This causes the blood flow in the veins to slow down and slow flowing blood is more likely to clot then normal flowing blood. Immobility caused by a surgical operation where you are asleep for over 1 hour is the biggest cause of a DVT, but illness that requires you to be on bed rest for a prolonged period of time, long journeys by plane or car and fractures that mean you need to where a leg cast also increase the risk of a DVT forming.
Damage to the inside of the vein wall
This could occur through needle use either recreationally or in a hospital, conditions such as vein inflammation (vasculitis) or medicines such as those used during chemotherapy.
Conditions that cause the blood to clot more easily
This includes thrombophilia, nephrotic syndrome and antiphospholipid syndrome. Some rare inherited blood disorders such as factor V Leiden mutation can also cause the blood to clot more easily. You are also at higher risk if a close family member has a history of DVT.
‘The Pill’ and Hormone Replacement Therapy (HRT)
Some contraceptives and HRT contain oestrogen can cause the blood to clot slightly more easily than those that do not contain oestrogen so women taking either of these have a small increased risk of DVT development.
People with cancer of heart failure
Sometimes a DVT occurs in someone who has undiagnosed cancer and while investigating the DVT, cancer shows up on the results and is attributed to the underlying cause of the DVT.
A lack of fluid in the body cause blood to become sticky and liable to clotting.
People over 60 with poor mobility, pregnancy, obesity and smoking all increase the risk of a DVT.
Males are more likely to develop a DVT than females.
It sounds like I’ve named just about everyone in the population, but it is estimated that 1 in 1000 people are diagnosed with a DVT in the UK, and roughly 1 in 3 people with a swollen, painful calf will have a DVT. If you can spot the signs and symptoms early and take measures towards preventing it from happening, such as drinking plenty of water and staying active (two things you should already be doing!) then you catch it early and can be treated without complications.
Pulmonary Embolism (PE)
This is where part of the blood clot has broken off, called an embolus, and travels through the bloodstream until it gets stuck. This usually happens in the blood vessels leading to a lung, because the blood vessels up the leg to the heart and the chambers of the heart are larger. This is a serious issue which is why seeing a GP when you first experience any symptoms is important – A small PE may not cause any symptoms. A medium-sized PE can cause breathing problems and chest pain. A large PE can cause collapse and sudden death. It is estimated that if people with DVT are not treated, about half of them would develop a PE large enough to cause symptoms or death.
Up to 4 in 10 people who have a DVT develop long-term symptoms in the calf if left untreated. This is called post-thrombotic syndrome. The increased flow and pressure of the diverted blood into other veins can affect the tissues of the calf, causing symptoms. Calf pain, discomfort, swelling and rashes are common symptoms and range from mild to severe. An ulcer on the skin of the calf may develop in very severe cases. Post-thrombotic syndrome is more likely to occur if the DVT occurs in a thigh vein or extends up into a thigh vein from a calf vein. It is also more common in people who are overweight and in those who have had more than one DVT in the same leg.