You are having a reaction to a medicine you have taken. This may not be the same as an allergic reaction. It's an unwanted side effect of a medicine. This can cause many symptoms, such as:
- Dizziness or headache.
- Rash.
- Flushing or a hot feeling.
- Nausea, vomiting, or stomach pain.
- Diarrhea or constipation.
- Trouble breathing.
- High or low blood pressure.
- Dark urine or blood in urine.
A reaction can be an upset stomach from something such as aspirin or ibuprofen. It can also be feeling faint after taking a blood pressure medicine, feeling anxious, and many other things. Symptoms can range from very mild to very severe.
In most cases, the reaction goes away in 1 to 12 hours. But it will likely happen again if you take this same medicine. Your doctor will advise you if you need to change how much, when, or how often you take this medicine. They may also advise you to stop using this medicine. Or your doctor may have you switch to another one. Ask your doctor if your symptoms were an allergic reaction or a side effect of the medicine.