Abdominal pain is very common in children, and in many cases there’s no serious cause. But stomach pain can sometimes point to a serious problem, such as appendicitis, so it is important to know when to seek help.

In most cases of amblyopia, the brain ignores signals coming from one eye. Over time, the brain gets used to working only with the other eye. So amblyopia must be treated as soon as possible.

Appendicitis, an infection of the appendix, is the most common reason for a child to need emergency abdominal surgery.

For some children, difficulty concentrating or very high physical energy levels (hyperactivity) interfere with social and academic tasks appropriate for their ages.

Autism is a developmental disability, usually showing up in children before age 3. It may be the result of a disruption in the development of the brain before a baby is born.

The common black-and-blue mark linked with any bruise is particularly evident when it surrounds the eye. The dark-purplish circle, commonly called a black eye, signals a bleeding injury and will last a little more than a week.

A child’s bones heal the same way as an adult’s. But since a child’s bones are still growing, there are a few special concerns.

Bruises form when blood cells seep from injured veins into surrounding skin tissue. Basically they are sores that don't break the skin. Newer bruises usually appear black and blue. As they heal they may look green and yellow.

Cellulitis is an infection of the deep layers of skin. Cellulitis can get into the bloodstream and lymph nodes and spread throughout the body, causing very serious illness. It is important for a child with cellulitis to get medical attention right away.

Chickenpox (varicella) is a very contagious viral disease. Normally a mild disease of childhood, chickenpox may be severe, especially in infants, adults, and people with impaired immune systems.

Anxiety disorders are among the most common emotional problems that occur during childhood and adolescence, and about half of the youngsters with these problems also have a second anxiety disorder or other mental or behavioral disorder, such as depression.

Asthma is the most common chronic illness among children. It causes a child's airways to become inflamed and tighten, and leads to coughing, wheezing and difficulty breathing. Asthma is unpredictable and affects each child differently.

It is estimated that up to 7 million U.S. children wet their beds on a regular basis and that one in five 5-year-olds is affected by the condition.

Croup is a general term for an acute condition that causes a brassy cough. It is usually caused by a viral infection that causes inflammation and swelling near the vocal cords, trachea (windpipe) and bronchial tubes (small airways) in young children.

Diarrhea is common in infants and young children because their digestive systems are still developing. A parent's job is to watch the child closely to make sure the child gets enough liquids and lots of tender loving care.

Although many parents tend to regard the presence of "earwax" in children as an embarrassing indicator of poor hygiene, this oily substance actually performs an important function in protecting the health of the ear.

Earaches in children are usually caused by an infection of the middle ear (otitis media), a pea-sized chamber located directly behind the eardrum. Two out of three children will experience at least one earache before they reach their third birthday.

Fever (temperature higher than normal) is not necessarily harmful, nor is it always evidence of an illness. A fever is a special cause for concern, however, in infants younger than 3 months of age.

Fifth disease is a viral infection that starts with a rash on the cheeks and then spreads to the arms and legs. Usually seen in children, from preschool through junior high school age, it often occurs in the spring.

Growing pains occur in children between the ages of 6 and 12. It is common for children having growth spurts to have vague aches and pains for no apparent reason. The pains usually occur in the evening, often in the calves and thighs.

Pinworms are a common parasite that affect mostly children. Pinworms are spread from person to person -- usually from child to child.

Anyone can get a rash, but babies and young children are particularly prone to them because their skin is still sensitive and they are likely to encounter bacteria and viruses as they begin to explore their world.

Nasal discharge or "runny nose" is a common occurrence among children. It is the result of the excess production of mucus. Although the condition may signal the presence of a cold, a sinus infection or an allergic reaction, it usually does not represent a significant health threat.

Improved awareness about oral health, the widespread use of fluoride, more consistent visits to a dentist and increased expectations among better educated parents has led to a decrease in tooth decay among the very young.

Although youngsters do not develop as many urinary tract infections (UTIs) as adults, recognizing and promptly treating a child's UTI is essential because, if left untreated, the infection can lead to serious kidney problems.

Vomiting in children is common and usually is not cause for concern if it occurs infrequently. It is important to give enough fluids and lots of tender loving care until your child's stomach settles down.

This is an extreme medical emergency. Knowing what to do can help save your baby's life.

Colic may be more harmful to worried and frustrated parents than it is to babies. Colic is common. No matter how hard it may be to cope with a colicky baby, colic is a harmless condition.

Your child is nearsighted if far away objects look blurry. Your child is farsighted if close-up objects look blurry. Other common eye problems: wandering eye, injuries and infections.

Your acne treatment will work best if you follow your treatment plan. Acne often takes months to improve, so you will need to be patient.

Children with epilepsy may have seizures only once in a while, or every day. Though seizures can be scary for parents and caregivers, they aren’t painful and are usually brief.

Coughing is a normal reflex that helps clear the lungs. Usually it is a minor annoyance, but sometimes a cough is a sign of a more serious condition. Most coughs are caused by postnasal drip, asthma, gastroesophageal reflux disease (GERD), or smoking.

The cause of cradle cap is not yet fully understood. Common in children less than 1 year old, cradle cap may be a mild form of seborrheic dermatitis. Cradle cap doesn't cause a baby discomfort and is easy to treat at home with self-care steps.

You can get an infection whenever your skin is broken, whether it's a scraped knee or a gunshot wound. They always should be treated to reduce the chance of infection or scarring.

Dehydration happens very quickly in the bodies of infants and small children, who don’t have as much fluid to spare. It can quickly become very serious. Rehydration is the crucial process of returning those fluids back to the body to restore normal functioning.

In most cases, the red bumps and blotches of this common condition are harmless and will disappear within three or four days, without treatment.

"Asthma is a disease with many triggers, including allergens and viral infections," says a clinical assistant professor of pediatrics. "But for a small set of patients, exercise is the sole trigger."

Down syndrome is the chief genetic cause of mild to moderate mental retardation. It occurs in 1 in 660 births, affecting all ethnic and socioeconomic groups.

Adults sometimes use inappropriate objects to clean their ears, causing damage that can be painful or that can result in hearing loss.

There are many possible causes of earaches. The most common: infection of the middle ear (otitis media), which is especially common in children. Other common causes of earaches can include swimmer's ear (otitis externa), earwax buildup and traveling on airplanes.

A growing number are children, usually girls, aren't overweight but believe they are. Magazines and TV shows that worship ultra-thin models and pop stars fuel the trend.

A scaly, red, itchy, dry rash can show up in the first weeks of life. It signals a vexing but treatable skin problem called atopic dermatitis (AD), often known as eczema. Most children outgrow AD, but in some cases, it may recur in the teenage years or in adulthood.

A fever is a way for the body to fight infection. But it may also be a sign of a serious illness, especially in children younger than 3 months and children who haven't been immunized. Know when to seek medical care for your child.

A foreign object in your eye should be taken seriously. If you feel something in your eye, don't rub it. Rubbing can damage the cornea (the clear tissue covering the colored part of the eye). Here's what to do.

GERD stands for gastroesophageal reflux disease ("acid indigestion" or "heartburn"). It happens when stomach contents flow back up (reflux) into the esophagus (the tube that connects the mouth to the stomach).

Hand-foot-and-mouth disease is a summertime disease, caused by the coxsackie virus, that afflicts mostly children. It is very contagious and is common in late summer and early fall. It is not related to hoof-and-mouth disease in cattle.

Lice feed on human blood. As they attach to the skin, their saliva causes intense itching. Left untreated, head lice are annoying and easily spread.

A hiccup is the sound that results when air entering the mouth and nose is cut off unexpectedly. People of all ages can experience hiccups anytime, anywhere.

Hives occur when an allergic reaction prompts cells to release histamine, a chemical found in the skin. Extensive outbreaks of hives can be very serious, such as when hives form on the lips and in the throat, interfering with breathing and swallowing.

One minute you and your child are laughing at the dinner table. The next minute the child is choking. Here's what you should do.

Your baby has been checked for jaundice each day while in the hospital. If you think your baby is yellow after you are home, you can check for jaundice yourself. Press the skin on the chest to see if it looks yellow when released. Darker skin babies can be checked by looking at the gums or whites of the eyes.

If your child’s legs aren’t completely straight, he or she may have bowlegs or knock knees. They are common in young children, but usually decrease as the child grows.

There’s no substitute for good old-fashioned loving care. Beyond that, if a child hasn’t had a fever for the past 24 hours and feels okay, he or she can return to regular activities. The following suggestions should help your child get back up to speed soon.

Fevers are only a symptom of something else happening in the body. Your child can have a fever and not look or feel hot. So always take your child's temperature for at least 1 minute before deciding how serious a fever is.

Although some children develop arches as their “baby fat” disappears, some children don’t. If not, it’s still considered normal, and usually not a cause for concern.

Most headaches in kids are caused by tension, not disease. Your pediatrician can determine what kind of headache your child has.

Children can become very ill -- and can have permanent damage -- after being poisoned by lead. Although you wouldn't deliberately feed your child lead, it is still present in many places.

Pitchers ages 10 and under can throw no more than 75 pitches a game. After that, they can't pitch until they rest for four days.

Type 1 diabetes can be controlled by taking insulin, eating a proper diet, and being active. These help your child’s body keep healthy blood sugar levels.

If a pregnant woman contracts rubella early in her pregnancy, the chance of birth defects can be as high as 80 percent.

Is your child overly restless or cranky—maybe tugging on an ear or talking about his or her ears “making noises”? If so, your child may have a middle ear infection.

Infectious mononucleosis, often called "mono" for short, is an infection, often mild, that can cause a fever, sore throat and enlarged lymph nodes. Most symptomatic cases of mono occur in teens and young adults.

When motion sickness occurs, motion receptors - your eyes, your inner ears, your skin, your muscles and joints - offer conflicting reports to your brain.

Blood vessels in the nose are near the surface, so even the slightest injury can cause a nosebleed. They occur more often in the winter, when viruses are common and air is drier. Most nosebleeds can be stopped with self-care, but occasionally they can be serious.

Oral thrush is a yeast infection that affects the mouth. Babies with thrush are often fussy and may have trouble feeding. Thrush is seldom serious in healthy children and adults.

Pertussis (also known as whooping cough) is a highly contagious infection of the respiratory tract. It spreads through droplets when an infected person coughs or sneezes. Because pertussis can be very serious, it's important to know when to seek medical care.

Pneumonia is a term that means lung infection. Though most children are able to get better at home with treatment from their doctor, pneumonia can be very serious and can require hospitalization.

The rash that occurs after contact with poison ivy, oak, or sumac is caused by urushiol, an almost invisible, clear-to-slightly-yellow oil that comes from any cut or crushed part of the leaves, stem, or vine crawling on the ground.

Prickly heat is an inflammatory skin disorder caused by the blockage of sweat ducts. Such blockages are usually triggered by dead skin cells or dried skin oil, which can clog affected pores and produce the burning and itching that characterize this condition.

R.I.C.E. stands for Rest, Ice, Compression, and Elevation. Doing these things helps limit pain and swelling after an injury.

Soft tissue may become trapped between the bones in a child's elbow joint (radial head subluxation). It usually occurs when a child is lifted or pulled by one arm.

Rheumatic fever is a serious, delayed complication of streptococcal infections, including strep throat and scarlet fever. It is an inflammation in the connective tissues throughout the body.

Ringworm is an outdated term for a fungal skin infection. The name ringworm -- dating back to the early fifteenth century -- comes from the idea that the infection was caused by a burrowing worm. There is no such thing as a ringworm.

Rotavirus is a germ that infects the small intestines. It is very common in the winter months, and is the leading cause of diarrhea in children.

Scabies produces small, itchy bumps that are caused by tiny mites. Like head lice, scabies is no longer thought to be a sign of poor hygiene.

Children’s eyes change rapidly, and problems can occur at any age. It’s important to observe your child’s eyes and to pay attention to how your child acts and what he or she says.

Most slivers are small wood splinters that do not penetrate deeply. Thorns, glass, or metal fragments can also be slivers. Slivers can be painful if pressure is applied to the affected area.

Minor fractures of the bone in the tip of the finger or toe are often left untreated. However, some fractures need to be splinted.

Sprains are stretched or torn ligaments, and occur most commonly at the ankle, knee, finger, or wrist. Symptoms include swelling, pain, and bruising.

Strabismus and amblyopia are two common vision problems in children. Your child won't outgrow strabismus or amblyopia, but both can be treated.

When your child has strabismus, the eyes aren`t aligned. If strabismus isn`t treated, the brain may start ignoring the eye that`s not aligned. This can lead to another vision problem, amblyopia.

Strep throat is an infection caused by bacteria. It mainly affects children between 6 and 12 years of age, but can affect adults too.

There are two types of UV rays that can damage skin. Ultraviolet A (UVA) rays are less likely to cause sunburn but can do damage below the skin; Ultraviolet B (UVB) rays are the main rays that burn your skin.

A foreign object may become stuck in the esophagus (food tube) or trachea (windpipe). In that case, your child needs prompt medical care.

Swollen lymph nodes are a mixed blessing. They usually are swollen because they're fighting an infection in your body. But because they often become enlarged quickly, swollen lymph nodes may be painful.

The tonsils are lymph nodes on each side at the back of the throat. They fight infection from bacteria and viruses, but sometimes the tonsils themselves can become inflamed and swollen. This is tonsillitis.

Youngsters' most common head pain is a tension headache—a dull ache that feels like pressure around the head.

Scrapes and sprains are a fact of life for most children, so it’s good to know what to do when they come home with a minor injury.

Your doctor will suggest the best treatment for you based on your age, how much more you are likely to grow, and the size and type of your spinal curve.

Viral respiratory illnesses include colds and flu. Treatment: relieve your child’s symptoms and ensure the infection does not get worse. Antibiotics are not effective against viruses.

Bulimia nervosa is a disorder in which food intake gets out of control. Having this eating disorder is nothing to be ashamed of. Talk to your doctor or another person you trust. You may find it’s a relief just to tell someone.

Conduct disorder is one of the most common emotional disorders in teens. It affects twice as many boys as girls. Behavior therapy can greatly help children with conduct disorder.

Osgood-Schlatter disease is a painful knee problem that can occur in active young people. It almost always gets better with rest and simple treatment.

For some children, the pain of certain events may be too much to bear. As a result, they may develop symptoms of posttraumatic stress disorder (PTSD). Fortunately, there is hope for children who suffer trauma.

Scoliosis is a problem that makes the spine curve and twist from side to side. It is most often found in girls in their early teens. But boys can have it, too.

Viral gastroenteritis is an irritation of the stomach and intestines due to infection with a virus. A child with gastroenteritis may have trouble keeping fluids down, and is at risk for dehydration and should be watched closely.

Most cases of viral meningitis occur in children under 5 years of age. Viral meningitis is usually mild and often goes away without treatment. It is much less serious than bacterial meningitis.

Warts are painless lumps on the outermost layer of the skin. They are slightly contagious. Most people have a natural immunity to warts and can't get them.

During the development of a fetus, the testicles (male sex organs) form near the kidneys. Normally, they’re in the scrotum before the baby is born. An undescended testicle doesn’t fully descend into the scrotum.

Acne is a skin condition that causes blemishes on the face, back, chest, or upper arms. In time, your acne may go away by itself. But treatment can help to control your acne now.

Dogs are responsible for 85 to 90 percent of all animal bites. But, many incidents can be avoided.

Known as heeleys, roller shoes, or street gliders, the shoes carry safety risks similar to those for inline skates.

Type 2 diabetes is a chronic (lifelong) condition. The good news is that diabetes can be managed. Your child’s healthcare team is there to help.