You have taken a medicine and something does not feel right. The order of operations matters: first check whether this is an emergency, then decide whether to keep taking it, then get advice, then record what happened. Working through those in order is safer than starting with a search for your symptom.

For background on how side effects work, see the medication side effects hub.

Start here: find the right side-effect guide

Category cards

Step 1. Rule out an emergency. If there is difficulty breathing, swelling of the face or throat, chest pain, fainting, a seizure, a blistering rash, blood in vomit or black stools, or thoughts of self-harm, get emergency help now. Do not wait to speak to a pharmacy.

Step 2. Do not stop a prescribed medicine on your own. Some medicines are dangerous to stop abruptly, including many for epilepsy, heart conditions, blood pressure, steroids and psychiatric conditions. Stopping can be riskier than the side effect. See should I stop taking my medicine.

Step 3. Get advice from the right person. A pharmacist can usually answer quickly and does not need an appointment. Your prescriber is the right contact for dose changes and for anything that has been going on for a while. See when to see a doctor and what to tell a pharmacist.

Step 4. Write it down, then report it. Keep the packaging and note the timeline. See reporting side effects in South Africa.

Common vs serious effects

The practical dividing line is what your response needs to be. A common effect is one you can reasonably discuss at the next opportunity: mild nausea, a headache in the first few days, some drowsiness. A serious effect changes your plan for today. If you are unsure which you are dealing with, treat it as the more serious of the two and get it assessed.

Common side effects vs serious side effects

Common examples linked to what to do if medicine causes side effects

Several everyday effects have a straightforward first step that a pharmacist will often suggest, though whether it applies depends on your medicine and your circumstances:

See also how to manage medication side effects and whether side effects go away.

How to describe frequency without overclaiming

When you describe what happened, stick to what you observed: what you took, when, what happened, and how it changed. Avoid presenting a conclusion. Saying that a medicine gave you a headache narrows the conversation, while saying a headache started on the second day of a new medicine and is worse an hour after each dose gives a professional something to work with.

Medicine, supplement and symptom categories covered

Priority related pages

How to choose the right next guide

If you are still deciding how urgent this is, read the serious side effects guide. If you have decided it is not urgent and want to know whether to continue, read the guide on stopping. If you are ready to speak to someone, skip both and prepare the record below instead.

When to speak to a doctor or pharmacist

Red-flag symptoms

Emergency care, immediately:

When to contact a doctor, pharmacist, or emergency service

Same day: yellowing of the eyes or skin, much less urine than usual, fever with a new rash, unexplained bruising or bleeding, or a new irregular heartbeat.

Routine appointment: effects that are mild but persistent, that stop you taking the medicine as prescribed, that affect your work or sleep, or that have not settled in the timeframe described in the leaflet.

When you make contact, have the medicine in front of you. Bring the box, not just the name, because strength and formulation matter and brand names differ between countries.

How side effects can be reported in South Africa

What information to record

Where reporting fits into medicine safety

Reporting is separate from treatment. It does not get you advice and it should never delay care, but it is how uncommon effects are found once a medicine is in wide use. SAHPRA accepts reports from members of the public in South Africa, and you do not need to prove the medicine was responsible. See the South African reporting guide and the reporting checklist.

Most useful next pages

Priority related pages

How to choose the right next guide

The four steps at the top of this page are the whole answer. Everything else on the site is detail on one of them. If you only do one thing, do step one, then speak to a pharmacist.

Medical Disclaimer: This content is for informational and educational purposes only and does not constitute medical diagnosis, prescription, or professional advice. Always read the patient information leaflet and consult a qualified doctor or pharmacist regarding any medicine or health concern.