Symptoms A–Z — Causes, Red Flags & When to Seek Help

Start from the symptom you have and read what it usually feels like, the conditions it can be associated with — common ones first — and the red flags that mean it should be checked promptly. Use the page to prepare for a conversation with your clinician, not to diagnose yourself: the same symptom can come from many different causes, and only an examination and, where needed, tests can sort them out.

No. A single symptom rarely points to one condition, and these pages deliberately list possibilities rather than conclusions. They can help you describe the symptom well, notice the patterns clinicians ask about — when it started, what makes it better or worse, what comes with it — and decide how quickly to seek care.

Call emergency services straight away for symptoms such as chest pain or pressure, severe breathlessness, signs of a stroke (face, arm or speech changes), fainting that does not recover quickly, seizures, uncontrolled bleeding, sudden severe headache, or confusion. Every page in this guide has its own red-flag list for that symptom.

Because likelihood depends on your age, your other symptoms, your medical history and an examination — things a webpage cannot know. The pages group causes with common ones first, which reflects how clinicians usually think, but that ordering is not a personal probability for you.

Where the MedicalVideos.com library has a fitting examination or clinical video, the page links to it — for example examination of the knee, the abdomen or the ear. Pages without a confident match show no video rather than an unrelated one.