On this page
- If this is happening right now
- The sentence that fills ICU beds
- Rule one — never stop insulin, even on a day you cannot eat
- Rule two — check your sugar far more often
- Rule three — fluids, in small sips, all day
- Rule four — eat what will stay down
- The signals that end home care
- What not to add to a sick day
- The other danger: sugar going too low
- Write the plan before the fever comes
- Related
- Frequently asked questions
If this is happening right now
Stop reading and act if any of this is true right now: breathing that has turned fast and deep, breath with a sweet or fruity smell, vomiting that will not stop, drowsiness, confusion, or a person with diabetes who is becoming difficult to rouse. Call 108. The ambulance network knows the nearest equipped centre, and PPK Hospital, Marthandam runs a 24/7 emergency department with intensive care and ventilator support behind it. Do not wait for morning, do not wait for the fever to break, and do not give anything by mouth to someone who is drowsy. This page is for the day before that — the ordinary fever, the two days of vomiting, the sick day that can either pass quietly or end in an intensive-care bed.
The sentence that fills ICU beds
“I wasn’t eating, so I skipped the insulin.” Every intensivist in this district has heard it, usually from a family standing beside a patient who is now on a drip with a monitor beeping over them. The logic is completely reasonable and completely wrong. Sugar — the word everyone here uses for blood glucose, sakkarai noi in Tamil, prameham in Malayalam — does not fall just because a plate goes untouched. Fever, vomiting, a chest infection or a foot infection all release stress hormones that push sugar up and blunt the insulin that is present. Take the insulin away on that day and, in type 1 diabetes especially, the body starts burning fat for fuel and flooding the blood with acid. That is diabetic ketoacidosis, and it can build over a single day.
Rule one — never stop insulin, even on a day you cannot eat
Insulin does two jobs. It covers the food that goes in, and it holds down the sugar the liver releases all by itself, all day, whether anyone eats or not. Illness increases the second job while removing the first, which is exactly why a sick day is the wrong day to stop. The rule is simple enough to keep on a phone screen: illness is not a holiday from insulin. If you cannot eat, or you have vomited more than once or twice, telephone your doctor the same day — the dose may well need adjusting, but that adjustment belongs to the doctor who knows your regimen and your kidney function. The same applies to tablets: ask which of yours, if any, should be held while you are ill, and never decide it yourself at the shop counter.
Rule two — check your sugar far more often
On a well day one or two readings describe your control. On a sick day they describe almost nothing, because illness can move a reading a long way within a few hours, and can move it in both directions — high from stress hormones, low from not eating while medication continues. So the sick-day habit is frequency: check considerably more often than usual, including once during the night if the illness is significant or the patient lives alone. Write every reading down with the time next to it rather than trusting memory or the meter’s screen. That little column of numbers is the most useful thing a family can hand the doctor, because it shows the direction things are moving in, which is the fact that decides whether a patient goes home with instructions or stays for observation.
Rule three — fluids, in small sips, all day
Dehydration is what turns a manageable sick day into a dangerous one. High sugar makes the kidneys pull water out of the body, fever adds to the loss, and vomiting or loose motions accelerate it — three taps open at once, in a climate where a fever in a tiled upstairs room in May does the rest. The practical instruction is small sips, very often, rather than a glass at long intervals: plain water, salted rice water, thin buttermilk, oral rehydration solution. Keep a bottle within arm’s reach of the bed, because what is within reach gets drunk and what is in the kitchen does not. Watch urine: passing very little, or dark urine, means the losses are winning, and that is a reason to be seen the same day rather than a reason to try harder at home.
Rule four — eat what will stay down
A sick day is not the day for a perfect diabetic diet. If insulin or tablets are continuing, something has to go in, and the target is simply carbohydrate that stays down — kanji, curd rice, thin dal, arrowroot, tender coconut water, small quantities taken often rather than a meal attempted and abandoned. The kanji that appears in every household here is a reasonable sick-day food, with one caution worth knowing: soft rice in liquid digests faster than firm rice, so keep the bowl thick and moderate, add whatever protein is tolerated, and expect the reading afterwards to need seeing. Is kanji good for diabetes? → If nothing at all will stay down for several hours, that is not a diet problem any more — that is a reason to come in.
The signals that end home care
These are seek-care triggers, not home protocols. There is no dose to adjust here and nothing to try first. Go in — or call 108 if the person is drowsy — when any of the following appears: vomiting that persists beyond a few hours or prevents fluids staying down; sugar staying above 300 mg/dL despite your usual treatment; breathing that turns fast and deep, the kind that is noticeable from across a room; breath that smells sweet or fruity; drowsiness, confusion or unusual behaviour; severe abdominal pain; or ketones testing moderate or high if you have strips at home. Any one of them is enough on its own. In an elderly patient, or someone living alone, add one more: not being able to manage the illness at home is itself a reason to be seen, and always the safer call.
What not to add to a sick day
Three additions make sick days worse. First, antibiotics bought over the counter for a fever nobody has examined — they treat nothing viral, delay the visit that would have found the real infection, and complicate the picture when the patient finally arrives. Second, painkillers taken freely during dehydration; if you take anything regularly, ask whether it should continue while you are ill and drinking little. Third — and this one is not about the fever at all — daily aspirin started on your own for “heart protection”. Guidance changed in 2019 and again in 2022, and routine self-started aspirin is no longer advised for people without established heart disease; it carries a real bleeding risk. Aspirin, statins and blood thinners may all be appropriate, but only after assessment, and only when prescribed for you.
The other danger: sugar going too low
Sick days cut both ways. The patient who takes their usual medication and then eats nothing all day can drop low, and low sugar moves far faster than high sugar does. Anything below 70 mg/dL is low and needs treating immediately with fast sugar — the 15-15 rule: about 15 grams of glucose or plain sugar in water, wait 15 minutes, check again, repeat if still low, then follow with something solid. Sweating, shaking, sudden hunger, irritability or confusion in a sick diabetic deserves a check rather than an assumption that it is the fever. If the person is drowsy or unconscious, put nothing in the mouth — no sugar, no water, no tablets — turn them on their side and call 108.
Write the plan before the fever comes
Sick-day rules fail because they are needed on the one day nobody is thinking clearly — at two in the morning, in a house where the meter’s batteries died in March. So build the plan while you are well. Ask at your next review which of your medicines continue during illness and whom to telephone. Keep the meter working, with spare strips and batteries. Keep oral rehydration sachets and a source of fast sugar in the house, and make sure the family knows where both live, not only the patient. Write the seek-care triggers on a sheet of paper and stick it inside a cupboard door. The households that keep a sick-day plan are the ones we tend not to meet in intensive care.
Related
Frequently asked questions
No. This is the single most dangerous decision a diabetic household makes during illness. Insulin is not only for the food you eat — it also holds down the sugar your own liver releases, which rises during any infection. If you cannot eat, telephone your doctor the same day. A dose may need changing, but that is a decision for the doctor who knows your regimen, never for the patient alone.
Far more often than on a well day. During fever, vomiting or a bad infection, readings can move within a few hours in either direction, so a single morning value tells you very little. Write each reading down with the time beside it, and carry that paper to the hospital — it shows the treating team the direction of travel, which matters as much as any one number.
Breathing that turns fast and deep, breath that smells sweet or fruity, vomiting that will not stop, drowsiness or confusion, sugar staying above 300 despite your usual treatment, or being unable to keep any fluid down. Any one of these means call 108 now, not in the morning — the ambulance network knows the nearest equipped centre, and PPK Hospital's emergency and intensive care run day and night.
Yes, with awareness. Kanji is often the only thing that will stay down, and eating something is better than eating nothing while insulin is on board. Keep the bowl moderate and thick rather than watery, add whatever protein is tolerated, and check sugar more often than usual — soft rice in liquid digests quickly, so the reading afterwards is worth seeing.
Anything below 70 mg/dL is low and needs treating at once with fast sugar — the 15-15 rule: about 15 grams of glucose or sugar in water, wait 15 minutes, then check again and repeat if it is still low. Follow it with something solid once you can. If the person is drowsy or unconscious, put nothing in the mouth at all and call 108 immediately.