A carbuncle is when multiple boils (or furuncles) form close together. It occurs because hair follicles next to each other become infected, causing pus-filled lumps that may converge into one larger lump. It is usually caused by bacteria known as Staphylococcus aureus, which is normally found on the skin or inside the nostrils in some people. It tends to cause no harm, although it can cause an infection, such as a boil, if it gets under the skin. Boils, or furuncles, look like red lumps that are painful and initially quite hard but, over the course of four to seven days, get softer as the amount of pus inside increases. The pus or infection can join together between each boil to become a carbuncle. You may see it progress to a white or yellow head on the lump. The skin around the boils may also become red and sore. The pus may come out of the boils on their own or be reabsorbed by the body. Once the pus is released, it can take around four to five days for the boil to heal, but it may leave a scar. The advice is not to try and burst the boil yourself, as it is not usually done cleanly and may lead to re-infection. While boils are quite common in male teenagers and young adults, carbuncles are mainly seen in middle-aged and elderly men, and you are more likely to develop them if you have diabetes or have a lowered immune system. They can be painful, especially as the amount of pus trapped inside increases. They are usually found in places on the body that are hairy while also being warm and moist, such as the neck or on the back. These conditions allow the bacteria to flourish, and any friction may cause small breaks in the skin, allowing the bacteria to get in.

Candida is a very common yeast causing a thrush infection. This gives rise to itching and soreness on the skin around the genitals and sometimes pain when passing urine. Warm damp conditions allow the yeast to grow, leading to a distinct bright red rash, often with small red bumps or pus-filled bumps around the edge. Soreness rather than itchiness distinguishes it from other causes of rash. This is more common in women than men and affects the labia (the outer and inner lips to the vagina), but it can spread to the groin and can cause itching and irritation to the inside of the vagina. You may also experience vaginal discharge, which is typically thick, white, and doesn't have any particular smell. Most people know it as thrush, but it's medically termed candidiasis or candidal vulvovaginitis if it affects the vagina. In men, this can affect the penis, causing candidal balanitis, and may cause some pain in passing urine.

Candidal balanitis is a common condition in men that causes the head of the penis to become inflamed. It is caused by candida, a very common yeast that can be found on our bodies. Typically it doesn’t cause any problems because it’s a very small amount however given the right setting, the yeast can multiply rapidly leading to an infection known as candidiasis (thrush). In men, it can affect the penis and foreskin, causing candidal balanitis. About 1 in 25 men will develop candidal balanitis at some point in their life.

Cancer occurs when cells in the body multiply out of control, producing lots of abnormal cells. These abnormal cells don't function like they should and can invade tissues or organs and sometimes spread to other parts of the body. Different cancers are due to different types of cells multiplying out of control. The most common types in the US are breast, prostate, lung, and bowel cancer, but there are many other types of cancer. Approximately 40% of people will develop cancer in their lifetime, which is a scary fact, but the treatments for cancer have improved tremendously over the years. Many cancers can be cured completely, particularly if caught early, so it's important to know about the signs to look out for and to seek medical advice early if you notice these. Any cancer fits into four stages, depending on the tumor size, whether it has spread, and how far. These are used to guide what treatment would be best. In Stage 1, the cancer is small and has not spread anywhere. Stage 2 is when the tumor is larger but hasn't spread. In Stage 3, the cancer is larger and has spread to nearby areas. Stage 4 is when the cancer has spread to other body parts and is known as metastatic cancer.

A bursa is a small fluid-filled sac that is located near the joints and acts as a cushion for the bones, muscles, and tendons. When a bursa becomes inflamed, the condition is called bursitis – and it leads to a red, swollen, painful, and stiff joint. This is commonly diagnosed based on history and examination alone, and no further investigation is usually needed. Commonly this inflammation occurs in the elbows, knees, shoulders, and hips, but you can suffer bursitis in any joint area of the body. Bursitis can be managed at home and usually subsides within a few weeks, but it can reoccur again in the future.

A bunion (or hallux valgus to give it its medical name), is a deformity of the big toe where - instead of pointing straight forwards - the big toe angles towards the second toe, causing a bony lump to form at the base of the big toe. This lump can rub on footwear and cause pain, swelling and redness around the area. At first the bony lump will be small but it can increase in size over time. There are things you can do to prevent the bunion from getting bigger and causing pain and difficulty walking.

Bulimia, also known by its longer medical name of bulimia nervosa, is a mental health condition and type of eating disorder. It can have a huge impact on people's day-to-day lives and can lead to further health problems, which in severe cases can be life-threatening if not treated. Symptoms and the severity of symptoms can vary from person to person. Still, bulimia is characterized by cycles of eating or binging on large amounts of food in a short space of time and then compensating for this by restricting food, inducing vomiting, using laxatives, or excessively exercising. The compensatory behaviors to try and avoid weight gain cause hunger and can lead to binge eating, which is why bulimia can be a vicious cycle of binging followed by purging or restricting. Along with this, poor body image specifically regarding weight, is also a common factor.

Bronchitis is an infection or inflammation of the bronchi, which are the largest airways of the lungs. These airways have a protective mechanism built into them where they produce mucus, which is meant to trap anything that is not welcome in the airways and that could be harmful to the lungs. When someone has bronchitis, something has irritated the airways, causing increased production of mucus. This leads to the body trying to get rid of the mucus, and causes a productive cough. Bronchitis can be short term (acute) or longer term (chronic). Acute bronchitis lasts around three weeks and is most commonly caused by a viral infection. The definition of chronic bronchitis is a chronic cough with mucus production for at least three months in two successive years when other causes have been excluded. Chronic bronchitis is a chronic inflammatory condition in the lungs that causes the respiratory passages to be swollen and irritated. It also increases mucus production and may damage the lungs. The symptoms are coughing and breathlessness, which will get worse over the years. When lung damage results in airflow restriction, the term chronic obstructive pulmonary disease (COPD) is used. Smoking is the most important cause of chronic bronchitis. Other things that make it worse are air pollution and allergy. The seriousness of the disease depends on how much and for how long a person has been smoking.

Bronchiolitis is a very common lung infection that occurs in young children, typically those under 2 years old, and is caused by a virus. The bronchioles are small airways in the lungs, branching off the two main bronchi, and the ‘itis’ part of bronchiolitis means inflammation, so bronchiolitis is inflammation and congestion of these small airways. Symptoms of bronchiolitis start off similarly to a cold with a blocked and runny nose, cough, and possibly fever. Children can also sound quite wheezy. Bronchiolitis is most commonly caused by a virus called respiratory syncytial virus (RSV) during the winter months and often it gets better on its own. In about 20% of cases of all ages, hospital admission may be required and it’s thought that up to 1 in 3 young children get bronchiolitis at some time.

A brain tumor occurs when a cluster of cells grows abnormally in the brain. These can affect you in different ways. It may not contain cancerous cells, in which case it is termed benign, but it may grow to a size that presses on important areas of the brain to cause symptoms. Alternatively, it may contain cancerous cells, in which case it disrupts the normal function of an area of the brain, even if it is a small size, and this is called a malignant tumor. If a benign tumor remains small and slow-growing, it may not cause any symptoms at all. Brain tumors can affect anyone at any age but are more common in adults than children. About 25,000 new cases of brain cancer are diagnosed in the US each year. On average, the 5-year survival rate is 32% after diagnosis.

BPPV stands for ‘benign paroxysmal positional vertigo’ and literally means dizziness when changing position, and without any sinister underlying cause. So, ‘benign’ means harmless, ‘paroxysmal’ means it’s sudden and brief, and ‘positional’ because the vertigo (the feeling like you’ve just gotten off a fairgrounds ride) is triggered by changes in your head position. The inner ear is a series of tubes that give us our sense of balance, as well as hearing, and in BPPV, tiny crystals collect in the tubes, disrupting this. It’s the most common cause of vertigo, the sensation of the room spinning around you. This gives brief episodes of dizziness lasting less than a minute, and usually triggered by certain head movements. BPPV can also cause a loss of balance and nausea or vomiting. BPPV is more common the older you get, and in most cases occurs as a result of age-related degeneration of the ear system. About a third of the population will have experienced BPPV by the time they’re 70, with the peak age being in the 50s and 60s. It’s rare in children and young adults. There’s no specific cure for BPPV, but it’s not usually a sign of anything serious, and will usually get better on its own after several weeks, although it can come and go.

Cancer occurs when cells in our body multiply out of control, producing lots of abnormal cells. These abnormal cells don't function like they should and can invade tissues or organs and sometimes spread to other parts of the body. Bowel cancer, also known as colorectal cancer, includes cancer of the colon (which is the large intestine) and cancer of the rectum (which is the last few inches of the large intestine before it turns into the anus). It is the third most common cancer in the US, affecting both men and women, and is more likely as we age. Certain genetic and lifestyle factors can increase your risk - we'll talk you through them. Symptoms of bowel cancer include blood in the stool, a change in your bowel habits for more than a few weeks, and a tending towards diarrhea, but may also tend towards constipation, too. Another symptom may be abdominal pain or discomfort and bloating. It is important to note that most people with these symptoms do not have bowel cancer, but if they persist, occur with older individuals, or occur with symptoms like loss of appetite, fatigue, and unintentional weight loss - this should be discussed with a doctor urgently. The Centers for Disease Control and Prevention (CDC) recommends that all adults aged 45-75 years be screened for colorectal cancer. Your doctor may recommend earlier testing if you are at higher risk. Results from this initial test will determine how often you should be rescreened. Evidence shows you can reduce the risk of developing bowel cancer by eating a high-fiber diet with lots of fruit and vegetables and avoiding processed foods. You should avoid smoking and excessive alcohol intake to lower risk, and keep fit and maintain a healthy weight.