At a glance
- The illness itself may be the main cause of fatigue.
- Check your particular medicine’s leaflet for known side effects.
- Ask a pharmacist about fatigue that worries you or does not improve.
- Seek urgent help if tiredness comes with serious new symptoms.
Illness and recovery take energy
A bacterial infection can leave you tired even after treatment has started. Other causes, including poor sleep, reduced eating or dehydration while unwell, may contribute. Fatigue by itself does not show whether the antibiotic is working.
If you are getting steadily better, recovery may still take time. If you are getting worse or have new symptoms, seek a professional assessment.
Could it be a side effect?
Side effects vary between medicines. Read your own patient leaflet; a pharmacist can help you understand whether tiredness, dizziness or another symptom could be linked to the medicine or warrants a check.
Do not stop or change a prescribed medicine based solely on a general article. Contact the prescriber if the effect is affecting your ability to function.
When to seek help
Seek urgent medical help if tiredness is accompanied by breathing difficulty, swelling of the face or throat, fainting, severe confusion or a rapidly worsening condition. For persistent or marked fatigue, speak to your doctor or pharmacist.
Sources
Original referencesThese sources informed this overview. Their organisations do not endorse or review this website.
This page is for general education only. It does not replace advice from a doctor, pharmacist or other qualified healthcare professional. Read our medical disclaimer.