Freshly Baked Science
I've Been Through a Clot
1st March 2019
Many women pop the pill as contraception or to ease period pain, but they may do this unaware of the harmful side effects that this medication can have. Our Chief Editor, Hannah, discovered the dangers of the pill the hard way when she found herself feeling breathless and experiencing chest pains. One misdiagnosis of asthma later, she found herself being whisked to hospital with a blood clot on her lung, fighting to survive. Defying the odds, she pulled through and sprung back, but unfortunately, countless other patients aren’t so lucky.
There are many types of contraception, but the pill is one of the most popular, thanks to its easy swallow-and-go properties. The most prescribed pill is the combined contraceptive pill, which contains 2 hormones: oestrogen and progesterone. Oestrogen and progesterone are naturally produced during pregnancy, to keep a baby in the womb until birth. Taking these hormones tricks the body into thinking it’s pregnant to prevent real pregnancy, after all, you can’t have two separate pregnancies at once.
Unfortunately, the pill isn’t a one-size-fits-all kind of solution as many people experience unwelcome side effects, like depression and weight changes. One of the more serious and lesser spoken about risks is blood clots.
Blood makes laps of the body as a liquid but needs to be able to solidify in response to injury, so that you don’t bleed to death (always useful). One component of blood responsible for making this happen is platelets. Like good friends, these cells are responsible for sticking together to form a plug at the site of an injury. To become sticky, platelets collaborate with a group of proteins called clotting factors.
Clotting isn’t always a good thing… it can be very dangerous when it occurs without an injury as a trigger. We call this abnormal clotting and it can form an unwelcome clot inside a vein or artery. If the clot is big enough, it creates a roadblock in the vessel which prevents normal blood circulation.
The blockage can dislodge and travel to different areas of the body, leading to one of three life-threatening conditions: a heart attack (blocks an artery leading to the heart), a stroke (blocks passage to the brain) or a pulmonary embolism (blocks an artery in the lung). These conditions account for around 544,000 deaths per year in Europe, more than AIDS, car crashes and breast and prostate cancer combined.
Taking the contraceptive pill increases the risk of abnormal clotting and associated conditions by 3-4 times. The oestrogen in the pill instructs cells to change production levels of certain clotting factors, including factor V, VII, VIII and S (thank you, science for the easy names).
Factor VII is increased the most, but not all factors are increased. The hormone instructs less of factor V to be produced. The decrease in factor V may seem beneficial, but it usually works with factor S to stop the production of factor VIII. So, in the absence of factor V, more factor VIII is produced, neutralising the benefit.
If you imagine clot formation and breakdown on either side of a weighing scales, in normal conditions this would be balanced. In conditions of high oestrogen levels, extra weight is added to the clot formation side, encouraging platelets to stick together. As oestrogen is also present in high levels in pregnant women, they are also at an increased risk of abnormal clotting.
Although the pill increases the risk, it usually isn’t enough to cause a blood clot too large to be broken down naturally, before complications. It mostly takes more than one risk factor for a significant blood clot to develop. Other risk factors include surgery, long periods of inactivity, family history of clots, smoking, obesity and clotting disorders.
At the moment, to assess a patient’s risk, doctors will simply ask if the patient smokes and if there is a family or personal history of clots. This may seem enough, but a recent study of women who experienced a clot revealed stats which question their clot prevention methods:
• 95% weren’t smoking at the time; 78% had never smoked
• 58% had no family history of clots
• 80% didn’t have a known disorder
Considering these stats, it’s clear that there is still much more waiting to be discovered about blood clots and their risk factors (where are our future haematologists?!). Due to this, it’s vital to know the symptoms to watch out for.
Get Clued Up
The symptoms vary with location and size of the clot; deep vein thrombosis (clot in leg or arm) tends to present itself with swelling of one limb, limb pain or tenderness and red or bluish discolouration and warmth to the skin. A pulmonary embolism can be detected by shortness of breath, chest pain, rapid heart rate and/or an unexplained cough.
As with coughs and cold, different people will have different variations on the symptoms. Some may only present with one symptom from the list and still be diagnosed, so be alert! If you think you or someone you know may be experiencing one or more of these symptoms, seek medical attention as soon as you can. It’s also important to note that the symptoms are often mistaken for other problems such as a Charley Horse or asthma, so don’t be afraid to pop back to the doctors if you are diagnosed with one of these but the symptoms persist.
Despite being aware of the risks and symptoms, many people have the ‘it won’t happen to me’ attitude. Taking the pill comes along with the responsibility of understanding what could go wrong and watching out for changes in your body. Stay safe and B positive (if you’ll pardon the pun)!