It is necessary to thicken water or tea in order to avoid choking on the drink.
How thick it should be depends on one's swallowing ability.
Of course, the taste goes down when one adds the thickening powder, and some drinks are harder to thicken. You can buy it in stores.
ご質問ありがとうございます。
"It is necessary to thicken water or tea in order to avoid choking on the drink."＝「飲み物にむせないために、水やお茶にとろみをつける必要があります。」
"How thick it should be depends on one's swallowing ability."＝「嚥下機能によりとろみを調整しなければいけません。」
"Of course, the taste goes down when one adds the thickening powder,"＝「当然、とろみをつけると味は落ちます。」
"and some drinks are harder to thicken."＝「そして飲み物によって、とろみがつきにくいのもあります。」
"You can buy it in stores."＝「お店でとろみは買えます。」
ご参考に。
アメリカ合衆国 
