Mariam Abdullah, a diabetic for 25 years, is aware of the complications if her condition is uncontrolled.
She monitors her blood sugar level, eats the right food, exercises and never misses taking her medication. This way, she does not have problems fasting during Ramadan.
"I've always been active and I eat right but I became more serious about my diet when I found out that I have diabetes. I eat only small portions of rice with steamed vegetables or skinned chicken twice a week. I like to walk or jog around my house," says Mariam.
The only problem she faced previously during Ramadan was a lack of energy because she did not have proper meals during sahur (pre-dawn meal). Since she was worried about eating too much, she avoided rice and carbohydrates, eating only fruit and vegetables with a glass of milk for sahur.
"I had to stop fasting a few days previously because I became weak. I realise my mistake and I now eat at least a bowl of rice at sahur. For buka puasa, I avoid food rich in carbohydrates, to control my blood sugar."
Mariam, 61, developed diabetes when she was pregnant with her youngest child.
Although her blood sugar level returned to normal after giving birth, the condition came back five years later.
"Once I had diabetes, I made sure I took my medication and followed the doctor's advice. My blood sugar level is only between six and seven and I do not have any complication."
Her daughter, Nor Salina Bee Mohd Nor, 36, has a different approach. She was diagnosed with diabetes due to obesity, 11 years ago.
"Unlike my mother, I did not control my condition when I was first diagnosed. I had eczema on my foot which caused an infection. Three years ago, when I became a single mother, I knew I had to change my lifestyle. I am now following the advice by the doctor and diabetes educator."
Nor Salina has to have insulin injections three times a day in addition to medication to control her blood sugar level. Currently her blood sugar level is 10 compared to 16 two years ago.
Despite her illness, Nor Salina has no problems when it comes to fasting.
"I did not change my diet completely but I eat smaller portions. I love food but now I am more aware of my diet. For sahur and breaking fast, I eat small portions of rice with vegetables and fish or meat. And I check my blood sugar level regularly."
Universiti Kebangsaan Malaysia Medical Centre senior consultant physician and endocrinologist Professor Dr Nor Azmi Kamaruddin says diabetic patients who fast during Ramadan must eat proper and adequate meals during sahur, drink a lot of water, make sure they inject their insulin, take their medication and check their blood sugar level as well as weight every day.
Since their medication is taken after meals, patients should not fast if they do not eat the pre-dawn meal. Medication lingers in body, causing blood sugar levels to go down if diabetics skip a meal. This causes dizziness, drowsiness, jitters and headaches.
"They think that if they do not eat during sahur, their blood sugar level will not go up. This is a misconception because the liver, which stores glucose, will immediately release it into the body if it detects low levels of insulin," says Dr Nor Azmi.
During the fasting month, patients should check their blood sugar level before sahur and two hours after that, because there is a tendency for it to drop because of lack of food. A blood test should also be done two hours before breaking fast.
According to research, patients develop hypoglycaemia (low blood sugar) within four to six hours after sahur and four to two hours before breaking fast.
"They also need to drink a lot of water - at least three glasses - during sahur or they may get dehydrated. The sugar in their bodies will be excreted in the urine together with water. If they are dehydrated, they risk falling into a coma."
Diabetics must check their weight every day during Ramadan. If they are losing weight too quickly, they should not be fasting. If they lose more than three per cent of their body weight a day, they will be in danger.
Patients with poor control of their condition and the elderly who live alone should not fast. This includes diabetic children who have not reached puberty.