Informational only — Not medical advice. Always consult a licensed healthcare provider.
ল্যাক্টোজ অসহিষ্ণুতা (দুধ হজমের সমস্যা)
Symptom information is not available for this condition yet.
⚠️ This symptom list is for educational purposes. Having these symptoms does not mean you have this condition. See a doctor for proper diagnosis.
⚠️ These medicines are commonly used for confirmed diagnoses of this condition. This is NOT a recommendation or prescription. Treatment must be determined by your doctor.
No medicines have been linked to this condition yet.
Lactose intolerance is a common digestive problem. The body can't digest lactose, a type of sugar found mainly in milk and dairy products.
Symptoms usually start within a few hours of eating or drinking something that contains lactose. They may include:
How bad your symptoms are, and when they appear, depends on how much lactose you've had. Some people can still drink a small glass of milk without any symptoms. Others can't even have milk in their tea or coffee.
Read more: Farting
The symptoms of lactose intolerance can look like those of several other conditions, so see your doctor for a diagnosis before you cut milk and dairy products out of your diet.
The same symptoms can also be caused by:
If your doctor thinks you have lactose intolerance, they may suggest you avoid foods and drinks containing lactose for two weeks to see whether your symptoms improve.
Read more: Irritable bowel syndrome (IBS) · Allergies
The body digests lactose with a substance called lactase. Lactase breaks lactose down into two sugars, glucose and galactose, and these can be absorbed easily into the bloodstream.
People with lactose intolerance don't make enough lactase. So the lactose stays in the digestive system, where bacteria ferment it. This produces various gases, and these gases cause the symptoms of lactose intolerance.
Whether the condition is temporary or permanent depends on why the body isn't making enough lactase. Most cases that start in adults are inherited and tend to last for life. In young children, though, the cause is often an infection in the digestive system, and it may last only a few weeks.
In the UK, lactose intolerance is more common among people of Asian or African-Caribbean descent.
It can develop at any age. Many cases first appear in people aged 20 to 40, though babies and young children can be affected too.
Lactose intolerance isn't the same as a milk or dairy allergy. A food allergy happens when your immune system reacts to a certain type of food, and that causes symptoms such as a rash, wheezing and itching.
If you're allergic to something, even a tiny particle can be enough to set off a reaction. Most people with lactose intolerance can still have small amounts of lactose without any problems, although this varies from person to person.
Read more: Food allergy
There's no cure for lactose intolerance, but cutting down on food and drink that contain lactose usually helps control the symptoms.
Depending on which dairy products you can eat, you may also need extra calcium and vitamin D supplements to keep your bones strong and healthy. In some cases, your doctor may refer you to a dietitian for further advice.
Besides changing what you eat, lactase substitutes may also help. These are drops or tablets you take with your meals or drinks to improve how your body digests lactose.
Milk and other dairy products contain calcium, protein and vitamins such as A, B12 and D. Lactose also helps your body absorb a number of other minerals, such as magnesium and zinc. All of these matter for building strong, healthy bones.
If you have lactose intolerance, getting the right amount of these vitamins and minerals can be difficult. That may lead to unhealthy weight loss, and it puts you at higher risk of developing the following conditions:
If you're worried that dietary restrictions are putting you at risk of these complications, it may help to see a dietitian. They can advise you on your diet and on whether you need food supplements.
You can also contact a private dietitian. The British Dietetic Association has information on how to find a private dietitian.
Read more: Osteoporosis · Malnutrition
Lactose intolerance usually happens because your body doesn't make enough lactase. Lactase is an enzyme (a protein that causes a chemical reaction to occur), and it's normally produced in your small intestine to digest lactose. If you have a lactase deficiency, it means your body isn't producing enough of it.
When you eat or drink something that contains lactose, it goes down your oesophagus (gullet) into your stomach, where it's digested. The digested food then moves on into your small intestine.
In the small intestine, lactase should break the lactose down into glucose and galactose (other types of sugar), and these are then absorbed into your bloodstream. If you don't have enough lactase, the lactose isn't absorbed. It carries on through your digestive system to your colon (large intestine).
Bacteria in the colon ferment (break down) the lactose, which produces fatty acids and gases such as carbon dioxide, hydrogen and methane. This breakdown of lactose in the colon, along with the acids and gases it produces, causes the symptoms of lactose intolerance, such as flatulence and bloating.
Read more: Farting
Primary lactase deficiency is the most common cause of lactose intolerance worldwide. It comes from an inherited genetic fault that runs in families.
The deficiency develops when your body makes less lactase because your diet relies less and less on milk and dairy products. This usually happens after the age of two, once breastfeeding or bottle-feeding has stopped. You may not notice any symptoms until adulthood, though.
Secondary lactase deficiency means your body is short of lactase because of a problem in your small intestine. It can happen at any age. Sometimes another condition is behind it, sometimes surgery to the small intestine, and sometimes certain medicine you are taking.
It is the most common cause of lactose intolerance in the UK, particularly in babies and young children.
These are the possible causes of secondary lactase deficiency:
The drop in lactase production is sometimes only temporary. If a long-term condition is the cause, though, it may be permanent.
You can also develop secondary lactase deficiency later in life without any other condition setting it off. This is because your body's production of lactase naturally falls as you get older.
Read more: Coeliac disease · Crohn’s disease · Ulcerative colitis
Congenital lactase deficiency is a rare condition that runs in families, and it shows up in newborn babies. It's caused by an inherited genetic fault, so affected babies make very little lactase, or none at all.
The faulty gene behind congenital lactase deficiency is passed on in what's called an autosomal recessive inheritance pattern. This means both parents must carry a copy of the faulty gene for a baby to inherit the condition.
Some babies are born early, before the 37th week of pregnancy, and they can have a temporary lactose intolerance. Their small intestine hadn't fully developed by the time they were born. Doctors call this developmental lactase deficiency, and it usually gets better as the baby grows older.
See a doctor if you think you or your child may have lactose intolerance, because the symptoms can look like those of other conditions.
Before you go, keep a diary of what you eat and drink and what symptoms you get. Tell the doctor if you notice any patterns, or if there are foods that seem to upset you more than others.
The doctor may suggest you take lactose out of your diet for two weeks and see if your symptoms ease. This gives more evidence about lactose intolerance, and it helps show if you really are lactose intolerant.
Most people with lactose intolerance don't need any other tests. Sometimes, though, your doctor may suggest further tests to help confirm the diagnosis, to find out how much lactase (the enzyme used to digest lactose) your body is producing, or to try to work out what might be causing your lactose intolerance.
Some of the main tests that may be used are described below.
A hydrogen breath test is a simple way to find out whether you may be lactose intolerant.
You'll be asked not to eat or drink anything during the night before the test. When you arrive, you'll blow into a balloon-like bag. This sample of your breath is checked to see how much hydrogen it contains, measured in parts per million (ppm).
You'll then be given a drink of lactose solution, and your breath will be tested every 15 minutes over the next few hours to see whether the hydrogen level changes.
If your breath shows a large amount of hydrogen (more than 20ppm above your baseline) after the lactose solution, it's likely that you're lactose intolerant. This is because lactose intolerance can make the bacteria in the colon (large intestine) produce more hydrogen than normal.
For a lactose tolerance test, you're given a drink of lactose solution. A blood sample is then taken from your arm with a needle, and it's tested to see how much glucose (blood sugar) it contains.
If you have lactose intolerance, your blood sugar levels will rise slowly, or not rise at all. That's because your body can't break the lactose down into glucose.
In a milk tolerance test for lactose intolerance, you're given a glass of milk (about 500ml) to drink, and then your blood sugar levels are tested. If your blood sugar doesn't rise after you've had the milk, you may be lactose intolerant.
Doctors rarely use a small bowel biopsy to diagnose lactose intolerance. It may be done, though, to check whether another condition, such as coeliac disease, is behind your symptoms.
In this test, the doctor takes a small sample of the lining of your small intestine. This is done with an endoscope, which is a thin, flexible tube with a light and a tiny cutting tool at the end, passed down your throat. You'll be given a local anaesthetic, so it won't hurt.
The sample is then tested to see how much lactase it contains. If there's only a small amount of lactase, you're likely to be lactose intolerant. The same sample can also be examined for signs of underlying conditions such as coeliac disease.
Read more: Coeliac disease
There's no cure for lactose intolerance, but most people can keep their symptoms under control by changing what they eat.
Some cases are only temporary. If lactose intolerance follows gastroenteritis, for example, it will improve within a few days or weeks. Other cases are likely to last for life, such as those caused by an inherited genetic fault or a long-term underlying condition.
For most people with lactose intolerance, cutting down on lactose or avoiding it, and swapping in lactose-free alternatives, is enough to keep the symptoms under control.
How much you need to change depends on how sensitive you are to lactose. Some people can take a little lactose without any trouble. Others get symptoms after eating food with only a tiny amount of it.
If you want to test what you can and can't eat, bring in new foods slowly, not all at once. That way you get used to any foods you might be sensitive to, and you can spot the ones that cause problems.
When you eat fewer products containing lactose, or none at all, you can miss out on certain vitamins and minerals, and your risk of complications goes up. So you'll also need to be sure you're getting enough nutrition, either from lactose-free foods or from dietary supplements.
If you or your child are extremely sensitive to lactose, talk to your doctor about your diet.
Milk products are rich in calcium, which your bones need to stay healthy, so you may need regular bone density checks.
You may be referred to a dietitian (an expert in diet and nutrition). They can advise on which foods should be part of your diet, or your child's.
Milk is a major source of lactose, and that includes cow's milk, goat's milk and sheep's milk. How much milk you need to cut back on depends on how mild or severe your lactose intolerance is.
For example:
If even a small amount of milk triggers your symptoms, there are some alternatives you can try, such as soya or rice milk (see below).
Butter, ice cream and cheese are also made from milk, and they can contain high levels of lactose. If you have lactose intolerance, you may need to avoid them.
Some dairy products, such as hard cheese and yoghurt, have less lactose than milk and the other products, so you may still be able to eat them. It's worth trying different foods to see which dairy products suit you, because dairy is a good source of essential nutrients such as calcium.
Milk and dairy products aren't the only things that can contain lactose. Some other foods and drinks can have it too. These include:
Read the ingredients of every food and drink product carefully, because milk or lactose are often hidden ingredients.
The lactose in some foods won't always be listed on its own on the label. So look through the ingredients list for milk, whey, curds and milk products such as cheese, butter and cream.
Some ingredients sound as if they contain lactose when they don't, such as lactic acid, sodium lactate and cocoa butter. If you're lactose intolerant, you don't need to avoid these.
Some prescription medicines, over-the-counter medicines and complementary medicines may contain a small amount of lactose. For most people with lactose intolerance, this isn't enough to bring on symptoms. It can cause problems, though, if your intolerance is severe or you're taking several different medicines.
If you need to start a new medicine, check with your doctor or pharmacist first in case it contains lactose.
If you have lactose intolerance, supermarkets stock a number of alternative foods and drinks to replace the milk and dairy products you need to avoid.
Foods and drinks that don't usually contain lactose include:
You can also buy cow's milk with extra lactase added (the enzyme used to digest lactose). This means you still get the nutritional benefits of the milk, but you're less likely to have any symptoms after drinking it.
If you can't eat most dairy products, you may not be getting enough calcium in your daily diet. Calcium does several jobs in the body, including:
So with lactose intolerance, it's a good idea to choose lactose-free products with added calcium, and to make sure your diet includes other sources of calcium, such as:
You can also buy combined calcium and vitamin D supplements from most pharmacists to help maintain good bone health. But check with your doctor or dietitian first about whether you should take supplements, because taking too much calcium can cause side effects.
Alongside changes to your diet, you may find it useful to take lactase substitutes, which come as liquid drops, tablets or capsules. Most health food shops sell them.
With lactose intolerance, your small intestine isn't making enough lactase. A lactase substitute replaces it, so your body can break down any lactose in your food more easily, and that can ease your symptoms.
You can either add the lactase substitute to milk or take it just before you eat a meal that contains lactose.
A child with lactose intolerance may be able to have small amounts of lactose without any symptoms. This is quite safe, but you may need to experiment a little to find out how much your child can comfortably eat or drink.
If your child can't tolerate any lactose, your doctor may refer you to a dietitian for advice on nutrition. Young children need certain nutrients in their diet for healthy growth and development.
In general, the rules about which foods to try and which to avoid are similar for children and adults (see above).
For babies, lactose-free formula milk is available to buy from pharmacies and supermarkets. Soya formula isn't recommended for children under six months, though, because it contains hormones that may interfere with your baby's future physical and sexual development.
Breastfed babies may benefit from lactase substitute drops, which help their bodies digest the lactose in breast milk.
For many children, lactose intolerance is only temporary and improves after a few weeks. After that, it's safe to bring milk and dairy products back into their diet gradually.
Milk and other dairy products are an important part of a healthy diet. They contain calcium, protein and vitamins such as vitamins A, B12 and D.
Lactose matters too, because it helps your body absorb a number of other minerals, including magnesium and zinc. These vitamins and minerals are important for the development of strong, healthy bones.
If you have lactose intolerance, getting the right amount of them can prove difficult. This may lead to unhealthy weight loss and put you at increased risk of developing the following conditions.
If you are concerned that dietary restrictions are putting you at risk of complications, you may find it helpful to consult a dietitian. They can advise you on your diet and whether you require food supplements.
You can also contact a private dietitian. The British Dietetic Association has information on how to find one.
Read more: Osteoporosis · Malnutrition
