Atresia is the medical name for when an opening, tube, or passage in the body hasn’t formed the way it should be. The opening might be blocked entirely, too narrow, or undeveloped. For example, ear atresia happens when the ear canal is not opened or fully developed.

Most people with atresia are born with this condition. Some kinds are obvious at birth. Other types of atresia show up later in childhood or even in adulthood.

Atresia can happen in any part of the body. Each kind of atresia is a separate condition that needs different treatment. Some types happen because of genetic conditions, while other types are not linked to genes.

A pregnancy doctor (obstetrician) may be able to see some kinds of atresia, such as heart atresia, even before a baby is born. Early recognition helps to have a treatment plan ready for right after birth.

The esophagus is the tube that connects the mouth to the stomach. Esophageal atresia happens when the tube ends before it reaches the stomach. Or, the esophagus might have divided into two tubes that don’t connect.

A baby with esophageal atresia can’t swallow or digest milk and other fluids. This serious congenital condition sometimes happens with another condition called a tracheoesophageal fistula.

The trachea is the breathing tube from the mouth to the lungs. A tracheoesophageal fistula occurs when a hole connects the esophagus with the trachea. This connection leaks fluid into the lungs, triggering serious infections and breathing problems.

Babies born with esophageal atresia, alone or combined with a fistula (hole), must have treatment. Surgery is needed to connect and repair the esophagus. Medical reviews show there’s about a 90 percent survival rate with surgery.

The heart has several openings and passageways to help move blood through it and the body.

All types of heart atresia make it harder for the body to get oxygen. General signs and symptoms include:

  • difficulty breathing
  • fast breathing
  • shortness of breath
  • getting tired easily
  • low energy
  • blue or pale skin and lips
  • slow growth and weight gain
  • heart murmur
  • clammy skin
  • body or leg swelling (edema)

Treatment includes medications to help the heart work more easily. More than one type of surgery may be needed to repair a heart atresia.

Several kinds of serious atresia can happen in the heart:

Aortic atresia

A baby with aortic atresia is born without a left ventricle, the opening from the left side of the heart into the main artery, the aorta. The left ventricle pumps oxygen-rich blood to the entire body.

This serious condition is rare. It makes up only 3 percent of all heart problems in babies. Surgery is needed to let blood flow through the heart and into the body properly.

Tricuspid atresia

Tricuspid atresia happens when a valve or doorway between two parts of the right side of the heart isn’t there. Instead, a wall forms between the two chambers — the right atrium and the right ventricle.

Tricuspid atresia makes it harder for the right side of the heart to pump blood to the lungs. The heart chambers may also be smaller than average. This condition can lead to heart failure in some babies and adults.

Pulmonary atresia

In this kind of heart atresia, the valve or opening between the heart and lungs is blocked. This makes it harder for blood to pick up oxygen from the lungs and carry it to the body. Pulmonary atresia happens at birth and must be treated right away.

Sometimes pulmonary atresia is part of another condition called Tetralogy of Fallot. This complicated heart condition also causes thicker muscles and a hole between two heart chambers.

Bronchial atresia is a rare condition in the lungs. It happens when some of the small tubes (bronchi) in the lungs get blocked. In some cases, mucus can get stuck in the blocked bronchi.

Signs and symptoms of bronchial atresia may not show up until later in childhood or an adult age.

They include:

  • cough
  • shortness of breath
  • lung infection

This condition is usually managed with medications, like antibiotics. Surgery is rarely needed.

Choanal atresia is when one or both nasal passages are blocked. This kind of atresia is rare. On average, 1 in every 6,500 babies may have it, and it’s more common in girls.

Symptoms include:

  • noisy breathing
  • difficulty breathing
  • breathing eased with crying
  • difficulty feeding
  • difficulty swallowing
  • fluids from the nose

The blockage in the nose can be made up of bone or bone and soft tissues. How serious this condition is depends on whether one or both nasal passages are blocked.

  • Bilateral choanal atresia. This is when both sides of the nose are blocked. It can be life-threatening because babies breathe mainly through their noses. It can also make breathing very difficult.
  • Unilateral choanal atresia. This happens when one side of the nose is blocked. It’s more common and less serious. Sometimes, it isn’t noticed until later in childhood, because the baby was able to breathe normally through one side of the nose only.

Babies with choanal atresia on both sides of the nose will need treatment right away. Surgery opens and repairs the nasal passageways. Sometimes a stent or tube is used to help prop open the nose after surgery temporarily.

Ear atresia can happen to the outer ear and opening, the ear canal, or both.

  • Microtia. Microtia happens when the outer ear is small, not formed properly, or entirely missing. The ear opening may also be little or blocked.
  • Aural atresia. In aural atresia, the inner ear parts are not correctly formed. The ear canal or opening, eardrum, middle ear, and ear bones might not be fully formed. Some children with ear atresia also have smaller outer ears or other changes to their ears.

A child can have atresia in one ear or both ears. Ear atresia can cause problems with hearing and hearing loss.

Children may need surgery to rebuild the ear canal. Some children with ear and microtia atresia have up to a 95 percent chance of getting normal levels of hearing with treatment.

Atresia can happen anywhere in the intestines. The different kinds of intestinal atresia are named for which part of the bowels they are in:

  • pyloric atresia
  • duodenal atresia
  • jejunal atresia
  • jejunoileal atresia
  • ileal atresia
  • colonic atresia

Some kinds of intestinal atresia can be diagnosed with a prenatal ultrasound before the baby is born. Too much amniotic fluid in the mother’s womb in the third trimester may be a sign of intestinal atresia.

Usually, a baby swallows amniotic fluid and passes it as urine. If there is an intestinal atresia, the baby can’t swallow and digest the amniotic fluid.

Other kinds of intestinal atresia are discovered after birth.

A newborn baby may have signs and symptoms like:

  • frequent vomiting
  • bloated or dilated stomach
  • bloating in only the top part of the stomach

Intestine atresia sometimes happens along with other birth defects and conditions. Babies with atresia anywhere in the intestines must have surgery to repair the bowels. Before surgery, the babies are given nutrition through the veins because they cannot eat or drink anything.

Once surgery has fixed the intestinal atresia, the baby can eat, swallow, and digest food normally. Gaining weight is a sign that the bowels are working properly.

Biliary atresia affects the liver. Babies who have this condition have blocked bile ducts inside and outside the liver. This backs bile up into the liver, causing damage.

This kind of atresia also slows down digestion. Your body needs bile to help digest fats. Without enough bile flowing to the intestines, food can’t be properly digested. This is why babies and small children with biliary atresia may become malnourished.

The main sign of biliary atresia is jaundice. This condition causes yellowing of the eyes and skin. It happens from too much bile in the body. Most babies with biliary atresia get jaundice by the time they are only three to six weeks old.

Other symptoms include:

  • swollen stomach
  • firm or hard stomach
  • bowel movements look pale or gray
  • urine has a dark color

Treatment for biliary atresia includes a special diet plan, taking nutrition supplements, and surgery. Some children will also need a liver transplant. Up to 90 percent of babies with biliary atresia recover with treatment.

Atresia in the ovaries is also called atretic follicle. It’s another kind of atresia that may happen in adults. People with this condition have blocked follicles in one or both ovaries.

Atretic follicles can damage or destroy eggs in the ovaries. A medical study on animals found that toxins from the environment, including BPA from some plastics, may make this condition worse.

People with atretic follicles may have difficulty getting pregnant or may be infertile. For people trying to get pregnant, managing this condition may include IVF treatments.

Atresia happens when an opening or passageway is blocked or did not form. Most kinds of atresia occur when babies are born. Some kinds may not be apparent until later in childhood or adulthood.

Treatment depends on the kind of atresia and symptoms. Some types of atresia will not need treatment.

Serious atresias will need medications and surgery. Surgery usually involves opening the blocked passageway or connecting blind ends.