Thickened fluids are often used for people with dysphagia

Dysphagia

Dysphagia is the medical term for the symptom of difficulty in swallowing. Although classified under "symptoms and signs" in ICD-10, the term is sometimes used as a condition in its own right. Sufferers are sometimes unaware of their dysphagia....

, a disorder of swallowing function. The thicker consistency makes it less likely that an individual with dysphagia will aspirate

Pulmonary aspiration

Pulmonary aspiration is the entry of material from the oropharynx or gastrointestinal tract into the larynx and lower respiratory tract...

 while they are drinking. Liquid thickness may be measured by two methods, with a viscometer or by line spread test.

There are several levels of consistency.

• Thin liquids: Unthickened, such as water or juice. Common thin liquids include coffee, tea, clear broth, clear juice, skim milk, 2% milk, and whole milk.
• Nectar thickened: Approximately as thick as a milkshake. Should pour in a continuous stream without "breaking" into drops. Common "natural" nectar thick liquids include nectar, tomato juice, and buttermilk.
• Honey thickened: Sticks to the sides of a cup like honey. Pours very slowly. Liquids include honey and cream soups.
• Pudding thickened: Will hold its shape when scooped with a spoon.

Patients who have a restriction to thin liquids should avoid ice cream, popsicles, and Jell-O as these melt into thin liquids in the mouth.

There are multiple commercial thickeners on the market which may be purchased to thicken liquids including THIXO-D ORIGINAL, THIXO-D CAL-FREE (Calorie free), SimplyThick, Thick-It, Thick & Easy, Thicken Right, and ThickenUp. Vendors are also preparing pre-thickened liquids such as water, juice, and milk in individual serving sized cartons.

There are a number of different substances used as thickeners:
SimplyThick uses xantham gum