Patient education: Thickening liquids (The Basics)

Why might I need to thicken liquids? — Some people have trouble swallowing foods or liquids. The medical term for this is "dysphagia." Sometimes, dysphagia happens if you eat too fast or don't chew your food well enough. It can also happen if the upper parts of your digestive system do not work as they should (figure 1).

If you have trouble swallowing foods or liquids, your doctor might refer you to a speech or swallowing specialist. This person can teach you exercises to help you swallow, and might also suggest ways to change your diet. It might not be safe for you to drink thin liquids. This is because they could get into your lungs and cause problems. This is less likely with thicker liquids.

Your doctor or nurse will tell you how thick your liquids need to be. They might also suggest working with a dietitian (expert on food and nutrition).

How does the doctor know that I need to have liquids thickened? — The doctor will do an exam and ask about your symptoms. They might order a swallowing evaluation from a speech therapist. For this, the therapist watches you swallow different liquids and foods. You might also need tests to check how well the muscles you use to swallow are working.

What are the different types of liquids? — There are 4 types of liquids (figure 2):

●"Thin" or "level 0" liquids - These are normal liquids that flow like water. You can drink them from a cup, or through a regular straw or nipple.

●"Slightly thick" or "level 1" liquids - These are thicker than water. You can still drink them from a cup or through a regular straw or nipple, but it takes more effort.

●"Mildly thick" or "level 2" liquids – These are nectar-thick. They can pour easily off of a spoon or run through the tines of a fork. Mildly thick liquids will leave a thin coat on the spoon. You can drink them from a cup. It will require mild effort to drink them through a regular straw.

●"Moderately thick," "liquidized," or "level 3" liquids - These are thick like honey. They slowly drip through the tines of a fork or come off of a spoon in drips or dollops. You can drink them from a cup. It will require some effort to drink them through a regular or wide straw. These can be swallowed directly and do not need to be chewed. You cannot mold or layer these liquids because they do not hold their shape. They have a smooth texture with no "bits" (such as lumps, fibers, bits of shell or skin, husk, or pieces of gristle or bone).

●"Extremely thick" or "level 4" liquids – These are pureed or pudding-thick. They sit on a fork or spoon and do not pour off. You cannot drink them from a cup or suck them through a straw. You need to eat them with a fork or spoon. These can be swallowed directly and do not need to be chewed. You can mold or layer these liquids because they hold their shape. They have a smooth texture with no "bits" (such as lumps, fibers, bits of shell or skin, husk, or pieces of gristle or bone). These liquids are not sticky, and the liquid does not separate from the solid.

How do I thicken liquids? — To make fluids thicker, use a commercial thickening powder or gel. Add the amount you need to get the right texture in your liquid, and mix well with a fork or wire whisk. Liquids should be smooth and not lumpy. Let the liquid rest for a few minutes to thicken. Test the liquid to make sure that it is the right consistency.

Foods can be "pureed" in a blender or food processor to create a softer texture. If a food is too thin when pureed, you can add thickener and then puree again. You can also try adding more of the food, potato flakes, infant cereal, cornstarch, or breadcrumbs. Adding powdered milk, protein powders, or breakfast powders can thicken liquid while also increasing the calories and protein in the liquid.

What do I do if the food isn't the right consistency? — If a food is too thin, try to add more of the thickener or other substance, and blend again.

If the food is too thick, add small amounts of liquids like gravy, broth, sauce, or milk, and puree again.

What else should I know?

●Do not leave your thickened liquid at room temperature for more than 3 to 4 hours. This will help keep your food safe.

●Do not use regular ice cubes in your thickened drinks. These will melt and make the drinks too thin. You can make your own ice cubes by freezing thickened water.

●Ice cream, gelatin, sherbet, and fruit ice will melt in your mouth and become a thin liquid. These need to be thickened with the thickening powder or gel.

●Do not change your diet, even if your swallowing gets better. Talk with your doctor or nurse first.

●You might need to avoid certain moist and juicy foods like oranges, grapes, or watermelon. These have thin juices that can easily get into the lungs.

●Make sure that your body is getting all of the nutrients it needs. This includes many different vitamins and minerals. If you are not sure that you are getting the right nutrients, your doctor, nurse, or dietitian can help.

More on this topic

Patient education: Dysphagia (The Basics)
Patient education: Acid reflux and GERD in adults (The Basics)
Patient education: Upper endoscopy (The Basics)
Patient education: Eosinophilic esophagitis (The Basics)
Patient education: Myasthenia gravis (The Basics)
Patient education: Esophageal stricture (The Basics)
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Patient education: Gastroesophageal reflux disease in adults (Beyond the Basics)
Patient education: Gastroesophageal reflux disease in children and adolescents (Beyond the Basics)
Patient education: Upper endoscopy (Beyond the Basics)