What are the different types of lactose intolerance?

Lactose intolerance is when the body is unable to digest lactose, a type of natural sugar. Lactose can be found in milk and yoghurt, among other dairy products. Lactose intolerance develops when your small intestine produces insufficient amounts of the enzyme lactase to digest and break down lactose. Undigested lactose passes through the small intestine and into the large intestine.

Lactose intolerance is the inability to adequately digest the sugar (lactose) found in milk. As a result, after eating or drinking dairy products, people have diarrhoea, gas, and bloating. Lactose malabsorption, often known as lactose intolerance, is normally painless, with only minimal symptoms.

There are three main types of lactose intolerance, each with different causes:

Primary lactose intolerance (normal result of ageing)

Lactose intolerance is caused by primary lactase insufficiency, which is the most frequent cause of lactose intolerance worldwide.

Lactase insufficiency of this type is caused by an inherited genetic flaw that occurs in families.
Lactase production reduces when your diet becomes less reliant on milk and dairy products, resulting in primary lactase deficiency.

Although the symptoms may not be obvious until maturity, this usually occurs after the age of two, when breastfeeding or bottle-feeding has discontinued

Secondary lactose intolerance (due to illness and injury)

Due to several infectious, inflammatory, or other diseases, injury to intestinal mucosa can cause secondary lactase intolerance. Common causes include:
• Gastroenteritis
• Celiac disease
• Crohn disease
• Ulcerative colitis
• Chemotherapy
• Antibiotics

Lactase levels may be restored if the underlying disorder is treated.

Congenital or developmental lactose intolerance (being born with the condition)

The defective gene can be passed on from parents to children, resulting in a complete deficiency of lactase in the baby. Lactose intolerance present at birth is known as congenital lactose intolerance. This Lactose intolerance is found in only a few cases

Your infant will be lactose intolerant in this condition. When human milk or a lactose-containing formula is fed, they will get diarrhoea. The illness can be life-threatening if it isn’t diagnosed and treated early on.
Dehydration and fluid loss are possible side effects of diarrhoea. Giving the baby lactose-free newborn formula instead of milk is a simple way to treat the condition.

Developmental lactose intolerance

Some babies born prematurely (before the 37th week of pregnancy) have temporary lactose intolerance because their small intestine was not fully developed by the time they were born.

This is known as developmental lactase deficiency and usually improves as affected babies get older.