NHS information on common rashes in babies and children, such as chickenpox, eczema, impetigo, ringworm, scabies, slapped cheek syndrome and more.
Find out why you might need to have a red blood cell (RBC) count and what the results could indicate.
Find out when to get medical advice if you have a red eye, and read about the most common causes.
Find out about reflux, where a baby brings up milk during or soon after a feed.
Find out more about the different types of lower and upper respiratory tract infections (RTIs) (airway infections), how the infections spread and when you should see a GP.
Find out about retinal migraine, a type of migraine that affects 1 eye, causing temporary vision loss and other eye symptoms.
Read about Rett syndrome, a rare genetic disorder that affects brain development and causes severe physical and mental disability from early childhood.
Find out about Reye's syndrome, including what the symptoms are, when to get medical help, how it's treated and how to prevent it.
Find out about the childhood infection roseola, including what the symptoms are, how to treat it and when to get medical advice.
Find out about rabies, including where it’s found, how you get it, how to avoid it and what the symptoms are.
Find out about radiotherapy, including what it is, how it works, when it's used, how it's given and the possible side effects.
Find out about Raynaud's phenomenon, a common condition that affects the blood supply to certain parts of the body, usually the fingers and toes.
Reactive arthritis is a condition that causes inflammation (redness and swelling) in various places in the body.
A rectal examination is where a doctor or nurse inserts a finger into your bottom (rectum) to feel for abnormalities. Find out why it's needed and what happens before, during and after the procedure.
Find out about repetitive strain injury (RSI), including what the symptoms are, what causes it, what you can do to treat it and when to get medical help.
Find out what restless legs syndrome (RLS) is, what causes it, and how it can be treated.
Read more about restricted growth, sometimes known as dwarfism, a condition characterised by short stature.
Rhesus disease (haemolytic disease of the foetus and newborn) is a condition where antibodies in a pregnant woman’s blood destroy her baby's blood cells
NHS information about rheumatic fever, including treatment, symptoms and causes.
Read about rheumatoid arthritis, a long-term condition that causes pain, swelling and stiffness in the joints.
Rickets is a condition that affects bone development in children. It causes the bones to become soft and weak, which can lead to bone deformities.
Find out about what happens in root canal treatment, including how it's performed, how long it takes and how successful it is.
Find out more about rosacea, a common long-term skin condition that mainly affects the face.
Find out about rubella (german measles), including what the symptoms are, what to do if you get it and the risks of catching rubella while you’re pregnant.
Find out about ringworm, including what the symptoms are, where to get medical help, how it’s treated, and how to stop it spreading.
Find out about retinoblastoma, a rare type of eye cancer that can affect young children.
Find out about the rotavirus vaccine, including why it's given, who should have it and what the possible side effects are.