Diarrhea is very common. It is usually caused by viruses and typically goes away on its own after a few days. But more severe diarrhea that lasts longer has to be treated. Otherwise it might lead to a dangerous loss of fluids and salts, particularly in children and older people.

Styes and chalazia are common and can occur at any age. The eyelid is swollen because a gland at the edge of the eyelid has become inflamed. If bacteria are involved, the swelling may develop very quickly and hurt. Styes and chalazia usually go away on their own.

In epilepsy, the brain or certain parts of the brain are too active. Some people have their first seizure in childhood, while others have their first seizure in older age. Medication can help to prevent seizures and maintain a good quality of life.

Being diagnosed with breast cancer often makes people feel very frightened and anxious. But if you get breast cancer for the first time and it hasn’t spread far, there’s a good chance that treatment can lead to full recovery. There are also many support services that help people in everyday life, to return to work and cope emotionally with breast cancer.

The typical symptoms of chickenpox are a very itchy rash with red blisters and a mild fever. This contagious viral infection mostly affects preschool and school-age children between the ages of two and ten. Although chickenpox is unpleasant, it rarely has any serious consequences in children who are otherwise healthy.

If you have already had chickenpox, you could get shingles later in life too. Both of these diseases are caused by the same virus. A weakened immune system, due to things like extreme stress or older age, can increase your risk of developing this often very painful rash. Shingles typically goes away within two to four weeks.

People often talk about having the flu (influenza) when they come down with a cold. The course of these two types of infections is very different, though. Colds start gradually, whereas flu viruses strike quickly and cause more severe symptoms. Read about the typical symptoms, the flu vaccine and the treatment options.

Most people get warts at some point. Warts are contagious and can be very persistent. Children and teenagers are particularly likely to get them because they often use public showers or changing rooms, for instance after doing sports or at the swimming pool. How can you prevent warts – and how can you get rid of ones you have?

Cystitis is very common in women. It is caused by a bacterial infection. The main symptom is a burning pain when peeing, often accompanied by an increased urge to pee. Uncomplicated cystitis can be treated effectively and usually goes away without much trouble.

Acute tonsillitis causes symptoms such as a sore throat, difficulty swallowing, fever and tiredness. Tonsillitis that keeps coming back within short spaces of time can be very distressing and in rare cases may lead to complications.

The typical symptoms of irritable bowel syndrome (IBS) include abdominal pain, constipation and diarrhea. Although IBS isn't dangerous, the symptoms can be very painful and bothersome. Read about the different treatment options and what outcomes can be expected.

When cataracts develop, the lens of the eye gradually becomes cloudy. Your vision becomes increasingly blurry – as if you were looking through a veil or fog. Some people's vision is only slightly affected, while in others it gets worse fast. Over the long term, only surgery will help.

Most teenagers will have pimples at some point. Severe acne can be very distressing. But there are a number of things that can help, although it usually takes a while to see results.

About one in five adults have varicose veins. These bumpy, bluish veins are mainly a cosmetic issue for most people. But they sometimes cause a feeling of heaviness, pain or cramps in the lower legs too. Read about the treatment options for varicose veins.

Cancer treatments can have serious side effects. Many people find chemotherapy-related hair loss on their scalp and body to be especially upsetting. The hair typically grows back a few weeks after the treatment.

Ejaculation is considered to be premature if "coming" too soon becomes a problem and affects a man’s sex life. Various treatment options are then available, including exercises for better controlling ejaculation, medication and sex therapy.

If a fungus grows a lot it may lead to a medical condition. Tinea versicolor is one example. This skin condition is caused by a yeast (fungus), and is usually harmless. Many people who have it don’t know that a fungus is to blame for their discolored skin patches. Read about the typical symptoms and effective treatments.

Hemophilia is a disease that causes problems with blood clotting. It makes blood clot (coagulate) much more slowly than usual. The worse the ability of the blood to clot, the more severe the symptoms. Read about the levels of severity, causes, effects and treatment options.

Canker sores (mouth ulcers) are among the most common medical conditions that affect the mucous membranes lining the mouth. When a canker sore develops, it might tingle and burn at first, and then become painful after that. These white-reddish spots usually heal on their own. Gels, creams or mouthwashes can help to relieve the pain.

Most of us are familiar with our teeth feeling somewhat “fuzzy” after eating sweets. But if your entire mouth feels cottony all the time, your sense of taste is impaired, and you’re having trouble swallowing, you may have oral thrush. Although this infection is rarely dangerous, it can be very unpleasant.

As we age, we may develop eye diseases that make it more difficult to see well, or that can sometimes have serious consequences. Glaucoma is one of those diseases. But loss of vision can be delayed or stopped if it's diagnosed and treated early enough.

Although menstruation is a normal part of a woman's life, severe period pain need not be. Women don't have to simply put up with it – menstrual pain can usually be treated effectively. If you have very painful periods or the pain gets worse over time, it can be a good idea to see a doctor.

Osteoarthritis of the knee typically starts with knee pain, at first only during or after movement. The risk is increased by things like being overweight or putting a lot of strain on your knees, for example if you kneel a lot. If osteoarthritis is advanced or can’t be relieved enough by exercise or painkillers, joint replacement may be considered.

Parkinson's disease is a disease of the nervous system. It typically occurs in old age and reduces the person's ability to move. Parkinson’s usually progresses slowly and can be treated effectively for a long time. Read about the symptoms, diagnosis, treatment options and everyday life with this condition.

Infertility can be caused by various things. One possible cause is a varicose vein in the scrotum, also known as a varicocele. Varicoceles are quite common. Read about the treatment options and which men can benefit from them.

Vaginal yeast infections are particularly common in women of childbearing age. The symptoms include itching, burning and abnormal vaginal discharge. They often go away after a short course of treatment with vaginal suppositories or creams.

Most parents will know what it's like to feel worried when their child has a hot, red face and high temperature. Fevers in children are usually caused by harmless viral infections. But it's still important for parents to know how to recognize the signs of a serious illness, and when it's a good idea to take their child to a doctor.

Before children can start getting by without diapers, they need to be capable of controlling their bladder and bowel. A whole series of bodily processes have to develop first to make that possible. How can you tell if a child is ready for potty training, and how can parents help make things easier?

Hepatitis is the medical term for an inflammation of the liver. It is often caused by an infection with certain viruses. Hepatitis B is mainly spread through blood and other body fluids. The risk of becoming infected with this virus is generally very low in Germany and similar countries.

Many people have high blood pressure (hypertension), but they usually don't notice it – which means that over time it can damage blood vessels. Having blood pressure that is always too high can make you more likely to have health problems like a heart attack, stroke or kidney damage.