When a patient has swallowing difficulty (dysphagia), the most common immediate step for caregivers in Hong Kong is to add thickener to all drinks and blend meals to a puree, in the belief that this keeps the patient safe. Many large randomised controlled trials and systematic reviews, however, show no evidence that thickening liquids or pureeing food reduces aspiration pneumonia, and they may lead to dehydration, malnutrition and a lower quality of life. What really improves the condition is a plan from the speech therapist covering swallowing exercises, systematic oral care and safe feeding strategies that can be carried out at home over the long term. This article takes this common myth apart one point at a time, and explains IDDSI texture levels, silent aspiration, swallowing exercises that have been shown to work, and how a home swallowing assessment builds training, care and the home environment into the patient’s everyday meals.
How swallowing difficulty affects health and safety
Many families treat slow eating and easy choking in an older person as a normal part of ageing. In fact, swallowing difficulty is common among older people in the community. It is closely linked to malnutrition, frailty and functional decline, and it is a hidden cause of repeated pneumonia and unexplained weight loss.
These figures show that swallowing difficulty is often overlooked, but that early screening and treatment can improve clinical outcomes considerably. In acute stroke, for example, swallowing screening alone lowers the risk of pneumonia by about 40% (OR 0.60, 95% CI 0.42–0.84; Yang 2021).
What is swallowing difficulty? Warning signs in eating, breathing and nutrition
Swallowing difficulty means that eating or drinking is obstructed, so that food or liquid can easily enter the airway. Besides coughing and choking, there are warning signs in breathing and nutrition. If any one of the three groups of signs below appears, a professional assessment should be considered.
Signs in eating
- Coughing or choking when eating or drinking
- A feeling of food stuck in the throat when swallowing
- A meal takes much longer, and each mouthful needs several swallows
- Food remaining in the mouth after eating, or more drooling
Signs related to breathing
- A voice that becomes wet or gurgly after meals, as if there is water in the throat
- Repeated fever with no clear cause
- Repeated pneumonia (aspiration pneumonia)
- Faster breathing after meals
Warning signs in nutrition and mood
- Unexplained weight loss
- Fear of eating or refusing to eat
- Drinking less, with a dry mouth and easy dehydration
- Going out or seeing friends less because eating is difficult
What is “silent aspiration”?
Many family members think an older person who does not cough while eating is safe, which is a dangerous misunderstanding. In some patients, food or liquid that enters the airway during swallowing does not trigger the cough reflex. This is called “silent aspiration” in medicine. Because there are no visible signs, families often notice the problem only when the older person has repeated fever, pneumonia or unexplained weight loss.
More than half of acute stroke patients have swallowing difficulty, and 20–47% of them develop aspiration pneumonia (Yang 2021). Some older people do not choke even when food enters the airway, which is called “silent aspiration”. If an older person has repeated fever, pneumonia with no clear cause, a wet or gurgly voice after meals, or unexplained weight loss, a swallowing assessment should be done early, even if there is no choking at mealtimes.
Common causes of swallowing difficulty
Swallowing is a complex physiological process that needs close coordination of the nervous system, muscles and sensory responses. The three main causes below damage this coordination at different points:
Are thickener and pureed food alone enough?
This is the central part of the article. Thickening drinks and blending meals to a puree looks like the safest approach, but medical evidence does not support the idea that thickening is the same as preventing pneumonia.
- All drinks are thickened and all meals blended to a puree, in the belief that this is “safe”
- In an RCT of 504 people with dementia or Parkinson’s disease, the three-month pneumonia rates in the chin-down swallowing, nectar-thick and honey-thick groups did not differ significantly (9.8% / 8.4% / 15.0%), and the honey-thick group was even higher (Robbins 2008)
- A systematic review found no convincing evidence that thickened liquids or pureed food benefit patients by preventing pneumonia (O'Keeffe 2018)
- Between half and two thirds of patients do not follow texture modification advice at all (50–66%; O'Keeffe 2018)
- Texture is assessed individually by a speech therapist against the IDDSI standard, and is not simply set to the thickest level
- Combined with trainable swallowing strength exercises (EMST, Shaker, effortful swallow)
- Systematic oral care and a correct feeding position are added, and this combination is the one with evidence for preventing pneumonia
- Safe oral eating and quality of life are kept as far as possible
In other words, thickening drinks or pureeing food can be part of the overall treatment plan, but it cannot replace swallowing exercise and oral care, and thicker is not always better.
Potential problems with thickened drinks and pureed food
Changing food texture across the board without an individual assessment not only fails to prevent pneumonia, but can also cause real harm to the patient.
Possible effects of changing food texture (O'Keeffe 2018)
- Patients given drinks with thickener often drink much less water, which increases the risk of dehydration
- Patients on pureed food over a long time have a higher rate of malnutrition
- Changing the texture of everyday food clearly lowers the patient’s quality of life
- As many as half to two thirds (50–66%) of patients do not follow the dietary advice, so the safety measures do not work
The home swallowing assessment
The real problem in swallowing difficulty often shows up at the table where the patient has meals every day. With a home clinical swallowing assessment, the speech therapist observes the patient in a familiar home setting, using the patient’s usual utensils and everyday food, and can pick up silent aspiration and problems at each stage of swallowing.
- 1Review of historyThe therapist first learns about the patient’s medical history, diet and medication, any earlier fever or pneumonia, and the current difficulties with eating.
- 2Oral function checkThe strength and range of movement of the muscles of the lips, tongue, cheeks and throat are checked, together with how sensitive they are.
- 3Trial feeding assessmentThe therapist observes directly how the patient swallows food of different textures and drinks of different thicknesses, and listens for changes in the voice after eating, to check for signs of silent aspiration.
- 4Advice and trainingThe food texture that suits the patient is set according to the IDDSI standard, and the family is taught on the spot how to help the patient with swallowing exercises, oral cleaning and safe feeding, so that they can follow the same steps at home.
An introduction to IDDSI, the international dysphagia diet standard
To give doctors, nurses, therapists, caregivers and food suppliers a consistent way of communicating, IDDSI (the International Dysphagia Diet Standardisation Initiative) is widely used internationally. It defines the texture of foods and drinks clearly through common levels, colour coding and numbers.
IDDSI divides texture into 8 levels (0–7). Drinks are levels 0–4 and foods are levels 3–7, and levels 3 and 4 overlap between drinks and foods. The scale has been validated and is highly correlated with the Functional Oral Intake Scale (FOIS) (R=.84, p<.001), so that different health professionals have a single standard for communicating food texture (Steele 2018).
| Drinks (0–4) | Drink levels run from thin like water (0) to extremely thick (4). Caregivers can use a simple 10-second syringe test at home to check whether the thickness of a drink is suitable. |
| Overlap (3–4) | Levels 3 and 4 cover both drinks and foods. They are transitional textures that can be drunk from a cup or eaten with a spoon. |
| Foods (3–7) | Food levels run from liquidised (3) and pureed (4) through soft and bite-sized (6) to regular food (7). Caregivers can use a fork or teaspoon for a simple test of whether the food texture meets the level. |
| Local alignment | The Hong Kong Council of Social Service (HKCSS) has issued a local guideline, 《照護食標準指引》, aligned with the IDDSI standard, which makes it easier for Hong Kong caregivers to buy ready-made care food of a suitable texture. |
Three directions in swallowing therapy: strength training, swallowing manoeuvres and posture
Many people wrongly believe that swallowing difficulty can only be accommodated by changing food texture for the long term. Swallowing is in fact a muscle function that can be improved by targeted training. The speech therapist designs a treatment plan from the assessment, combining the three areas below:
Swallowing strength training
- Expiratory muscle strength training (EMST): exercises the muscles used for breathing out and coughing
- Shaker head-lift exercise: exercises the suprahyoid muscles that pull the chin down and the larynx up, to reduce food left behind after swallowing from entering the airway
- Effortful swallow: swallows with more force and helps the base of the tongue to push back more closely
Swallowing manoeuvres and posture
- Chin-tuck swallow: tucking the chin slightly while swallowing narrows the entrance to the airway and protects it
- Mendelsohn manoeuvre: holds the larynx raised for longer during the swallow, to help the entrance of the oesophagus to open
- Sitting upright, taking small mouthfuls and swallowing slowly, to reduce the chance of food entering the airway
Research data on swallowing strength training: EMST and the Shaker exercise
These exercises are clinical methods supported by randomised controlled trials, and the benefit lasts for some time. This is an important reason to support patients in keeping up practice at home.
Troche 2010 gave Class I evidence that swallowing strength can be raised by training. Troche 2014 found that even 3 months after training stopped, strength fell back by only about 2% and was still 17% above baseline, which shows that a habit of regular daily practice allows the benefit to continue. Logemann 2009 showed that the Shaker exercise and traditional therapy each have their own targeted benefits, so the therapist should choose a suitable plan for each patient.
Three key points in preventing aspiration pneumonia: oral care, swallowing exercise and feeding technique
Thickening alone does not get to the root of the problem, so what does work? The answer is to combine care, training and the environment. Oral care is the part most easily overlooked, yet it has good research evidence.
- Systematic oral care—A Japanese randomised controlled trial (RCT) in 11 nursing homes with 417 older people found that when carers cleaned the older person’s mouth after every meal, with a weekly session of professional oral care, there were clearly fewer older people with pneumonia, fewer days of fever and fewer deaths from pneumonia (Yoneyama 2002). This shows that reducing the bacteria in the mouth lowers the chance that, if choking happens, it develops into pneumonia.
- Swallowing screening and exercise—Early swallowing screening clearly lowers the risk of pneumonia after acute stroke (OR 0.60, 95% CI 0.42–0.84; Yang 2021). Targeted swallowing exercise after that makes eating safer.
- Correct feeding position and environment—Sitting upright while eating, taking small mouthfuls slowly, staying focused, and sitting for a while after eating all reduce the chance of food remaining in the throat or flowing back into the airway.
Home checklist for safe feeding
Caregivers can go through the safety checklist below at each feeding, to put the therapist’s professional advice into daily care.
- Make sure the patient sits upright (about 90 degrees) with the head not tipped back
- Keep the environment quiet and do not feed with the television on, so that the patient is not distracted
- Prepare food and drinks at the IDDSI level the therapist recommends, and do not thicken them further yourself
- Give small amounts slowly, and feed the next mouthful only when the patient has swallowed the last one completely
- After eating, check the mouth for leftover food and help the patient clean the mouth
- After the meal, keep the patient sitting upright for 20–30 minutes before lying down
- If the voice becomes wet or gurgly, the colour looks wrong or there is repeated fever, stop feeding at once and seek help
When should tube feeding be considered?
When the risk of oral eating is too high and safety cannot be assured, the medical team discusses tube feeding (such as a nasogastric tube or gastrostomy) with the family. There is no general answer to whether the earlier tube feeding is started the better, and it must be weighed carefully for each person.
Data from the FOOD multicentre randomised controlled trial (RCT) show that, in stroke patients with swallowing difficulty, early percutaneous endoscopic gastrostomy (PEG) in the acute phase carried a 7.8% higher risk of death or poor outcome than a nasogastric tube (95% CI 0.0–15.5, p=0.05). The results do not support PEG very early in acute stroke (FOOD Trial Collaboration 2005). Whether to use tube feeding is a medical decision that depends on the condition at the time, and it does not mean the patient can never eat by mouth again. Patients and families should discuss with the doctor and speech therapist, and keep the ability to eat by mouth as far as is safe.
How home speech therapy fits in with daily life
The benefit of swallowing exercise depends on enough intensity and on keeping it up, and the familiar home environment is the best setting for this.
Frequently asked questions
Treatment and recovery for swallowing difficulty often need a team of professions working together. If the patient also has speech and communication difficulty after stroke, see treatment for language disorders. To help family members learn practical skills for daily swallowing care and feeding, see the home training and caregiver guide. For more about our services, visit the home speech therapy main page.
Worried about a family member’s eating safety or repeated pneumonia? Our registered speech therapists can carry out a swallowing assessment at home, set individual texture advice according to IDDSI, and demonstrate swallowing exercises and feeding strategies that can be kept up at home.
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