Symptom checker
Symptom checker
Choose a body area and a symptom to see the common causes, the warning signs that mean you should get urgent help, and links to full, plain-English guides.
Education and reference only — this is not a diagnosis. A symptom can have many causes, and this tool cannot examine you or tell you what is wrong. It helps you understand possible causes and, above all, recognise when to seek help. If you feel very unwell, trust that and get medical help. Call 999 for an emergency (for example severe chest pain, difficulty breathing, or signs of a stroke — face drooping, arm weakness, slurred speech). For urgent advice that is not an emergency, call NHS 111.
Browse everything
All symptoms by body area
Prefer to browse? Every symptom below links to its full guide — causes, self-care and red flags.
Heart, chest & breathing
Head, brain & nerves
Mental health & mood
Eyes & vision
Ear, nose & throat
Mouth, teeth & jaw
Skin, hair & nails
Bones, joints & muscles
Stomach & digestion
Sexual & reproductive health
General & whole-body
- Blue lips or skin
- Chills and shivering
- Cold or discoloured hands and feet
- Cold sweats
- Excessive hunger
- Excessive sweating
- Excessive thirst
- Fatigue
- Feeling cold all the time
- Feeling faint
- Fever
- Frequent infections
- Hot flushes
- Muscle weakness
- Night sweats
- Swollen glands
- Unintentional weight loss
- Weight gain
- Yellow skin or eyes
Answers
Symptom checker: frequently asked questions
Can this symptom checker diagnose me?
No. It is educational and cannot examine you or tell you what is wrong. A symptom can have many causes; this tool helps you understand them and — most importantly — recognise when to seek help. Always have your own symptoms assessed by a clinician.
When should I call 999 or NHS 111?
Call 999 for an emergency such as severe or crushing chest pain, difficulty breathing, signs of a stroke (face drooping, arm weakness, slurred speech), a fit, or a rash that does not fade under a glass in someone who is unwell. For urgent advice that is not an emergency, call NHS 111. Each symptom lists its own specific red flags.
Where does the information come from?
From our own plain-English symptom and condition guides, which are clinically reviewed and referenced to sources such as NICE CKS. The tool simply lets you explore that library by symptom. See our Quality & Editorial Policy.
Is my data stored?
No. The checker runs entirely in your browser — nothing you select is sent to or stored on our servers.
Understand a condition in full
Browse plain-English, clinically reviewed guides to conditions, medicines and tests.