Body & Fitness

What you need to know about blood thinners

What are they, why might you need them, and what are the side effects?

If your doctor puts you on blood thinning medication, it’s because there are concerns about your blood clotting. But taking these drugs is not just a simple matter of popping a pill every day.

Here’s what you need to know about blood thinners:

Why do you need blood-thinning drugs?

Doctors may put you on this type of medication if they consider you to be at risk of developing a blood clot. Clots form when blood cells clump together and can stop the flow of blood to the heart or brain, causing a heart attack or stroke.

How do blood thinners work?

Some medications keep blood thin by stopping blood cells from sticking together in the veins and arteries. These are known as antiplatelet drugs. Others increase the amount of time it takes for clots to form – these are anticoagulants.

Do you have to be careful about taking them?

Yes. They must be taken exactly as directed. If you don’t take enough, the medication won’t be effective.

If you take too much, you can suffer from severe bleeding. For example, if you cut yourself, you could have trouble stopping the blood flow.

When you are on blood thinners, your doctor may get you to take blood tests to check the rate at which your blood clots. This test will show if your clotting is within the safe range. If it isn’t – for example if it clots too fast or too slow – you could be at risk of bleeding excessively or clotting too easily. Your medication may need to be adjusted

Can anything interfere with how the drugs work?

Yes, various foods, herbs and medications can affect the drugs. Not all thinners are affected by the same substances. Your doctor should supply you with a list of foods and medications the particular drug you are taking can react with. Make sure you read it and if you are not sure about anything, ask your doctor.

Vitamin K is responsible for regulating clotting and excess levels of it in your blood can lessen the effectiveness of some anticoagulants, like warfarin.

Some foods high in vitamin K that you may need to go easy on – or avoid altogether – include cruciferous vegetables such as cabbage, broccoli and Brussels sprouts. Also be wary of spinach, lettuce, kale, asparagus and endive.

Herbs that can interfere with the anti-clotting abilities of thinners include:

• Chamomile

• Echinacea

• Evening primrose oil

• Ginseng

• Gingko biloba

• Golden seal

• Dong quai

• Licorice

• St John’s Wort

• Willow Bark

Some foods act as natural anticoagulants and may help to prevent your blood from clotting. But there can be risks associated with them if you are prescribed blood-thinning medication because you may become more prone to excess bleeding. Check with your doctor about whether you should be eating any of the following:

• Garlic

• Ginger

• Celery

• Aniseed

Foods that are rich in vitamin E are also natural blood thinners.

Be wary of:

• Olive oil

• Spinach

• Tomatoes

• Kiwifruit

• Mangoes

• Broccoli

• Peanut butter

• Sunflower seeds

• Almonds

Alcohol and cranberry juice can also affect blood thinners. Talk to your doctor if you drink these.

Prescription and over-the-counter medications can also react with thinners and cause problems. Some antibiotics, pain relievers (such as ibuprofen), anti-fungal drugs and acid reducers can increase the risk of bleeding. Always read the small print that comes with them and if in doubt, check with the pharmacist.

Other drugs, including birth control, can decrease the effects of anticoagulants, meaning you may be at greater risk of developing a clot.

Do blood thinners have side effects?

They can in some people. Excessive bleeding is usually the most common side effect. You may notice your periods are heavier than usual, you’re more prone to nosebleeds and bleeding gums and, if you cut yourself, it bleeds more than normal.

There may also be blood in your urine or faeces – make sure you get this checked out as it could also be a sign of bowel or bladder problems.

In severe cases, thinners can result in excessive bleeding that may cause a type of brain haemorrhage known as an intercranial haemorrhage.

Do I need to be cautious if I’m on blood thinners?

Don’t wrap yourself in cotton wool but if you are on a blood-thinning drug, you might want to avoid contact sports or activities where you have an increased chance of suffering cuts and grazes. Take care using sharp knives!

How do I know if thinners are bad for my health?

If you have other symptoms, such as the ones below, go to the doctor immediately:

• Heavy menstrual bleeding

• Coughing up blood

• Blood in the urine or faeces

• Dizziness or weakness

• Severe headache or stomach ache

Bones beware

Some blood thinners can lead to deficiencies in vitamin D and calcium, which may, in turn, result in the weakening and thinning of bones. If your doctor prescribes a thinning drug, talk to him or her about whether you may need to take supplements to counteract these possible depletions.

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