Like all medicines, low-dose aspirin can cause side effects, although not everyone gets them.
Common side effects
Common side effects of low-dose aspirin happen in more than 1 in 100 people. There are things you can do to help cope with them.
Mild indigestion
Take your aspirin with food. If the indigestion still does not go away, it could be a sign that the aspirin has caused a stomach ulcer. Talk to your doctor – they may prescribe something to protect your stomach or switch you to a different medicine.
Bleeding more easily than normal
Because aspirin helps to stop your blood from clotting, it can sometimes make you bleed more easily. For example, you may get nosebleeds and bruise more easily, and if you cut yourself, the bleeding may take longer than normal to stop. Be careful when doing activities that might cause an injury or a cut. Always wear a helmet when cycling. Wear gloves when you use sharp objects like scissors, knives, and gardening tools. Use an electric razor instead of wet shaving, and use a soft toothbrush and waxed dental floss to clean your teeth. See a doctor if you're worried about any bleeding.
Talk to your doctor or pharmacist if the side effects bother you or do not go away:
Serious side effects
It happens rarely, but some people have serious side effects after taking aspirin.
Call your doctor or call 111 now if:
- you are coughing up blood or have blood in your pee, poo or vomit
- the whites of your eyes turn yellow or your skin turns yellow (this may be less obvious on brown or black skin), or your pee gets darker – these can be signs of liver problems
- the joints in your hands and feet become painful – this can be a sign of high levels of uric acid in the blood
- your hands or feet swell – this can be a sign of water retention
Stomach ulcers
Aspirin can cause ulcers in your stomach or gut, especially if you take it for a long time or in big doses.
Your doctor may tell you not to take aspirin if you have a stomach ulcer, or if you've had one in the past.
If you're at risk of getting a stomach ulcer and you need a painkiller, take paracetamol instead of aspirin as it's more gentle on your stomach.
Serious allergic reaction
In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to aspirin .
Immediate action required: Call 999 now if:
- your lips, mouth, throat or tongue suddenly become swollen
- you're breathing very fast or struggling to breathe (you may become very wheezy or feel like you're choking or gasping for air)
- your throat feels tight or you're struggling to swallow
- your skin, tongue or lips turn blue, grey or pale (if you have black or brown skin, this may be easier to see on the palms of your hands or soles of your feet)
- you suddenly become very confused, drowsy or dizzy
- someone faints and cannot be woken up
- a child is limp, floppy or not responding like they normally do (their head may fall to the side, backwards or forwards, or they may find it difficult to lift their head or focus on your face)
You or the person who's unwell may also have a rash that's swollen, raised, itchy, blistered or peeling.
These can be signs of a serious allergic reaction and may need immediate treatment in hospital.
Do not drive yourself to A&E.
The person you speak to at 999 will give you advice about what to do.
Other side effects
These are not all the side effects of aspirin. For a full list see the leaflet inside your medicines packet.
Reporting side effects
You can report any suspected side effect using the Yellow Card safety scheme.
Visit the Yellow Card website for more information about reporting side effects.