Read about balanitis, which is where the head of the penis is swollen and sore. Find out about the symptoms, causes, treatments and when to get medical help.
Read about having a barium enema, including what you need to do to prepare, what happens during the test, and what happens afterwards.
Find out about bedbugs, including checking if you have them, how to get rid of them and how to treat bedbug bites.
Read about a group of medicines called beta blockers, including what they're used for, side effects and what to do if you miss a dose or take too much.
Find out more about a black eye, which is bruising and swelling around your eye, usually caused by a blow.
Read about blood clots, their symptoms, when to get help and how to prevent them.
Find out about blood groups. There are 4 main blood groups – A, B, AB and O.
Find out about possible causes of blood in semen and when to get medical help.
Find out about blood in urine (pee). It's not usually anything serious, but sometimes it can be, so you must get it checked out by a GP.
Find out why a blood pressure test is important, how it’s done and what your blood pressure reading might mean.
Read more about boils and carbuncles, which are red, painful lumps on the skin that are usually caused by a bacterial infection.
Find out about botulism, a rare but life-threatening condition caused by toxins produced by Clostridium botulinum bacteria.
Find out about bowel (colonic) polyps, which are small growths on the inner lining of the bowel. There are often no symptoms but should usually be removed.
Find out about the symptoms, causes and treatments for Bowen's disease, a very early and easily treatable form of skin cancer.
A brain tumour is a growth of cells in the brain that multiplies in an abnormal, uncontrollable way. Find out about its symptoms and how it's treated.
Find out about breast pain and what can cause it. It's usually linked to periods but can also be caused by injury, infection and taking certain medicines.
Find out whether you might be eligible for breast reduction surgery on the NHS and what to do if you think you might qualify.
Find out about breath-holding in babies and children, including when to get medical help, what happens during an episode and what to do.
Find out how to tell if your ankle is broken (fractured) and when to get medical advice, plus how a broken ankle is treated and how long it takes to heal.
Find out how to tell if you have a broken arm or wrist, where to get medical help and how long it takes to heal.
Find out how to tell if you have a broken collarbone, where to get medical help and how long it takes to heal.
Find out how to tell if you have a broken finger or thumb, what you should do, and how long it takes to heal.
Read about the signs of a broken leg, what you should do if you think someone has broken their leg, how a broken leg is treated and how long it takes to recover.
Find out about the signs of a broken nose, how to look after your nose at home and when you should seek medical advice.
Find out about how long it takes injured ribs to heal, how to look after yourself until you're feeling better, and when you should get medical advice.
Find out about the symptoms of a broken toe, when you should get medical advice, and how to look after it at home.
Find out about bronchitis, what the symptoms are, how you can ease the symptoms, where to get help, and how it is treated.
Find out about brucellosis, including symptoms, what to do if you have it and treatments.
Find out about Brugada syndrome, including what the symptoms are, when and where to get medical help, the causes and how it's treated.
Find out about blue or grey skin or lips (cyanosis), including what it looks like, what causes it and when to get it checked.
Find out about bladder pain syndrome (BPS), also called interstitial cystitis, where you have pelvic pain and problems peeing.
Information for people with vision loss including details of support organisations, plus advice about specialist equipment, home modifications and mobility.
Find out how to relieve back pain, what can cause it, and when to get medical advice.
Read about bacterial vaginosis (BV), a common cause of unusual vaginal discharge. BV is not a sexually transmitted infection (STI).
Find out what causes bad breath (halitosis), how to treat and prevent it, and when to get medical advice.
Find out what a Baker's cyst is, what causes it, how it's treated and when to see your GP.
Find out what a Bartholin's cyst is, what the symptoms and causes are, and the possible treatment options.
Find out what you can do about bedwetting, what could be causing it and when to get medical help.
Read about Behçet's disease, a rare and poorly understood condition in which blood vessels and tissues may become inflamed (swollen).
Find out more about Bell's palsy, a condition that causes temporary weakness or paralysis of the muscles on 1 side of the face.
Information about benign (non-cancerous) brain tumours, including types of tumour, when to see a GP, causes, treatment and recovery.
Find out more about having a biopsy, which involves taking a small sample of body tissue so it can be examined under a microscope.
Find out about birthmarks, including information about 6 of the main types, when to see a GP, and whether or not treatment is needed.
Bladder cancer is where a growth of abnormal tissue, known as a tumour, develops in the bladder lining. In some cases, the tumour spreads into the surrounding muscles.
Read about bladder stones and what causes them. Also, find out when to see a GP and how bladder stones are treated.
Bleeding from the bottom (rectal bleeding) is often seen as small amounts of bright-red blood on toilet paper or pink water in the toilet. Find out when to get medical help if you keep bleeding from your bottom.
NHS information about blepharitis, including the symptoms, when to get medical help and what you can do to treat and prevent it.
NHS information about blisters, including how to treat blisters yourself, how to avoid getting them, and when to get medical help.
Find out about blood tests, including why they’re done, how to prepare, what happens at the test, and when you’ll get your results.
Find out how to stop yourself blushing and read about the possible causes and treatments.
Find out more about primary bone cancer, a rare type of cancer that begins in the bones. Around 550 new cases are diagnosed each year in the UK.
Find out NHS information about bone cysts, including how they're treated and what causes them.
Information on bowel cancer screening with links to other useful resources.
Read about bowel incontinence, including the symptoms, what causes it and the treatments available.
A brain abscess is a pus-filled swelling in the brain. It's a rare and life-threatening condition, usually caused by infection or a severe head injury.
Find out what a brain aneurysm is, including why they develop, who's affected, how they're treated and how to prevent them.
Brain stem death is where a person no longer has any brain stem functions, and has permanently lost the potential for consciousness and the capacity to breathe.
Find out about breast abscesses, including what the symptoms are, where to get help, how they are treated and what causes them.
Find out about breast lumps. They can have a lot of different causes and most are harmless. But always see a GP if you have a lump in your breast or any unusual changes to your breasts.
Read about bronchiectasis, which is a long-term condition where the airways of the lungs become widened. This leads to a build-up of excess mucus that can make the lungs more vulnerable to infection.
Find out more about bronchiolitis, including the symptoms, how it's treated, and what causes it.
Read about bronchodilators, a medication used to treat asthma and COPD by relaxing the muscles in the lungs and widening the airways (bronchi).
Find out what can cause the eye to bulge and what treatments may help.
Burns and scalds are damage to the skin caused by heat. Both are treated in the same way.
NHS information about bursitis, including symptoms, when to get help, treatments and prevention.
A DEXA scan is a type of X-ray that measures bone mineral density (BMD). It's also known as a DXA, dual X-ray absorptiometry, a bone density scan or a bone densitometry scan.
NHS information about broken hip (hip fracture) including what the symptoms are, how it's treated and recovery.
Read about benign prostate enlargement (BPE), also known as benign prostatic hyperplasia (BPH), which is a common condition in men over 50 years of age.
Bird flu, or avian flu, is an infectious viral illness that spreads among birds. In rare cases, it can affect humans.
Find out about blood transfusions, including when you might need one, how they're carried out and associated risks.
NHS information about bunions, including symptoms, how they're treated and how to help prevent them.
Read about bullous pemphigoid, a rare skin condition that usually starts with an itchy, raised skin rash and then as the condition develops, large blisters can form.
NHS information and advice about how to treat body odour, including when to see a GP if the problem persists.
This guide includes all you need to know about caring for your baby.
Find out about NHS breast screening, including when you'll be invited, how to book, what happens and what your result means.
Find out about common causes of bloating, what you can do about it and when to get medical help.
Find out about braces and orthodontics, including how much they cost on the NHS or privately, and how to care for your teeth while wearing braces.
Find out about bowel cancer, including what the symptoms are, what to do if you think you have it, how it is treated, and where to get support.
Understand more about bile duct cancer, its symptoms, when to get medical help, testing and diagnosis, treatment and where to find help and support.
Anyone can get breast cancer. Find out about breast cancer in women, including what the symptoms are, what to do if you think you have it, how it is treated, and where to get support.
Anyone can get breast cancer. Find out about breast cancer in men, including what the symptoms are, what to do if you think you have it, how it is treated, and where to get support.
NHS information and advice about body dysmorphic disorder (BDD or body dysmorphia), including what the symptoms are and what can help.
Bipolar disorder, previously known as manic depression, is a condition that affects your moods, which can swing from one extreme to another.
Read about bulimia nervosa, an eating disorder and mental health condition where someone is binge eating, then making themselves vomit or using laxatives to purge the food from their body
Read about binge eating disorder, which is when a person feels compelled to overeat on a regular basis. Find out about the symptoms, treatments and possible causes.
Read about borderline personality disorder. Personality disorders can cause a range of distressing symptoms and patterns of abnormal behaviour.
Find out about the BCG vaccine for tuberculosis (TB), including who should have it and possible side effects.