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Why Thickened Fluids Are Needed

For people with dysphagia, thin liquids — water, tea, juice, soup broth — move too quickly through the oral and pharyngeal phases of swallowing. Before the airway can be protected, liquid can spill into the larynx and trachea, causing aspiration. Thickening fluids slows down the bolus, giving the swallowing reflex more time to trigger and the airway more time to close.

In Hong Kong, thickened fluids are prescribed for an estimated 15–20% of elderly care home residents, and are routinely used in acute hospital wards and home care settings following stroke, Parkinson’s disease, dementia, and other neurological conditions.


IDDSI Fluid Levels 0–4: What Each Level Means

The IDDSI framework defines five fluid thickness levels for dysphagia management, all testable using a standard 10 ml syringe:

LevelNameFlow Test (10 ml syringe, 10 sec)Common Example
Level 0Thin>10 ml flows freelyWater, tea, broth
Level 1Slightly Thick1–10 ml remains in syringeSome fruit nectars
Level 2Mildly ThickPours in a thin stream; leaves a coatingThick cream soups
Level 3Moderately ThickFalls off spoon in dollopsHoney-like consistency
Level 4Extremely ThickCannot be drunk from a cup; eaten with a spoonPudding-like consistency

The most commonly prescribed levels in Hong Kong care settings are Level 2 (for mild dysphagia) and Level 3 (for moderate dysphagia). Level 4 is used when pharyngeal control is severely impaired.

Always follow the specific IDDSI fluid level prescribed by your speech-language pathologist. Do not approximate — using Level 2 thickener when Level 3 is prescribed significantly increases aspiration risk.


Starch-Based vs Xanthan Gum Thickeners

There are two main types of thickening agent used in clinical and home settings in Hong Kong:

Starch-Based Thickeners

Examples: Cornstarch (粟粉), modified starch thickeners (e.g., Nestlé Resource ThickenUp starch variant)

PropertyStarch-Based
TextureOpaque, paste-like, slightly grainy
Hot liquidsContinues to thicken over time — can overshoot target level
Cold liquidsThickens reliably
TasteCan affect flavour; slight starchy aftertaste in high doses
SyneresisLiquid separates from gel over time (less stable)
Saliva interactionAmylase in saliva breaks down starch — consistency thins in the mouth
CostGenerally lower cost

Key concern: Because salivary amylase degrades starch, the consistency in the mouth is thinner than measured in the jug — meaning starch thickeners may underperform at the critical airway-protection moment.

Xanthan Gum Thickeners

Examples: Nestlé Resource ThickenUp Clear, SeniorDeli Clear Thickener, Nutilis Clear

PropertyXanthan Gum-Based
TextureClear to translucent — does not change drink appearance
Hot liquidsStable at high temperatures — suitable for hot tea, coffee, soup
Cold liquidsThickens reliably; stable in cold carbonated drinks
TasteMinimal flavour impact; preferred by patients for taste retention
SyneresisMinimal — gel remains stable for hours
Saliva interactionNot degraded by salivary amylase — consistency maintained in the mouth
CostHigher cost per serving; partially offset by lower dose required

Clinical preference: Most Hong Kong SLTs now recommend xanthan gum-based thickeners for their consistency stability and taste neutrality. The lack of salivary amylase degradation makes them more reliable for achieving the prescribed IDDSI level at the point of swallowing.


SeniorDeli Clear Thickener

SeniorDeli Clear Thickener is a xanthan gum-based thickening agent formulated for Hong Kong clinical and home care use. Key features:

Available at: seniordeli.com/products/clear-thickener

Free delivery to all areas of Hong Kong on orders above HK$200. Same-day dispatch for orders placed before 1:00 pm (Monday–Friday).


Where to Buy Thickeners in Hong Kong

SourceProducts AvailableNotes
seniordeli.comSeniorDeli Clear Thickener, Resource ThickenUp Clear, Nutilis ClearOnline delivery; widest range for home users
Watsons / ManningsSelected starch-based thickenersLimited range; may not carry xanthan gum variants
Hospital Authority pharmacyResource ThickenUp (prescribed only)Available after SLT referral and pharmacy script
Medical supply shops (醫療用品店)Various brandsQuality varies; verify IDDSI compliance before purchase
ParknShop / WellcomeGenerally not stockedCare food products not routinely available in supermarkets

Practical Tips for Using Thickeners at Home

  1. Measure accurately — use the dose table on the packet; do not estimate by eye. 0.5g deviation at Level 3 can reduce the consistency to Level 2.
  2. Add thickener to liquid, not liquid to thickener — pour the powder into the drink while stirring continuously to prevent lumping.
  3. Allow resting time — xanthan gum thickeners typically reach target consistency within 30–60 seconds; starch-based thickeners may take 1–2 minutes. Always allow full resting time before testing consistency.
  4. Use the IDDSI syringe test to verify consistency before each meal — a 10 ml syringe is inexpensive and available at most Hong Kong pharmacies (ask for a feeding syringe, 注射器).
  5. Store dry powder in an airtight container in a cool, dry place. Do not store in the refrigerator — humidity causes clumping.
  6. Thickened drinks do not freeze well — prepare fresh each time; do not batch-freeze thickened fluids.

Frequently Asked Questions

Q: Can I use cornstarch (粟粉) from the supermarket as a thickener?

A: Supermarket cornstarch is not recommended for clinical dysphagia management. It requires heat to activate, has unpredictable thickening in hot vs cold liquids, and is significantly degraded by salivary amylase. Clinical-grade xanthan gum thickeners provide consistent, predictable results.

Q: Are thickeners covered by CSSA or elderly vouchers in Hong Kong?

A: Thickeners are not covered by the CSSA food allowance. Some NGO programmes and hospital social work departments can assist with supply for eligible patients. Ask the hospital medical social worker before discharge.

Q: My relative refuses thickened water because it tastes different. What can I try?

A: Xanthan gum-based clear thickeners have minimal taste impact. Try thickening flavoured drinks (mild fruit juice, mild tea) at Level 1 or 2 rather than plain water — flavour acceptance is consistently higher. Ensure the drink is served at the patient’s preferred temperature.


Content reviewed by the softmeal.org editorial team. For product enquiries: [email protected].