Sleeping more than the required seven hours can make you lethargic, depressed, anxious and less productive. If you’re prone to headaches, sleeping longer than usual can also be a trigger, says Dr Christina Low, medical director at Lifescan Medical Centre. Oversleeping is also linked to obesity, back pain and an increased risk of heart disease.

“When you drink too much water too fast, such that it is beyond your kidneys’ capacity to excrete the excess fluids as urine, you run the risk of water intoxication, which can be potentially fatal,” says Dr Hoe Wan Sin, a GP at Parkway Shenton. “This happens as the sodium levels in the blood fall to a dangerously low level, leading to brain swelling.” So how much is enough? “You should drink enough such that you rarely feel thirsty and your urine is colourless or light yellow. And this works out to at least 1.5 litres a day.”

“Over-exercising can cause muscle soreness, muscle and joint stiffness, and fatigue. When your muscles and joints are stressed, you may sustain injuries like hamstring strains, Achilles tendon tears or shoulder-joint problems,” Dr Low points out. It can also prevent you from functioning optimally. Having a regular exercise regimen is a good way to prevent osteoporosis, and boost your immunity and emotional well-being. Dr Hoe recommends about 2.5 hours of aerobic exercise a week plus muscle-strengthening exercises two days a week.

Dr Sherina Daryanani, a dentist at Teeth @ Tiong Bahru, Dental Clinic, recommends brushing your teeth first thing in the morning and last thing at night. Three times a day is fine, too, but unnecessary. Any more than thrice a day, and you risk wearing down the surface of your teeth and cause gum recession, which could expose the softer root surface and lead to tooth sensitivity. Another common problem is when you brush too hard. This could traumatise the gums, causing soreness in the short term.

“Even with gentle pressure, using a cotton bud could cause hearing loss, damage your ear canal or rupture your delicate ear drum. And while a punctured eardrum will heal, it can also lead to conductive hearing loss,” says Dr Low. You don’t need to clean your ears as they are self-cleaning, but if you must, just clean the outer ear with a washcloth, using a mild soap and warm water, advises Dr Low.

Most nutrition experts agree that if you have a healthy, well-balanced diet, you don’t need vitamin and mineral supplements. Overdosing on dietary supplements can have a range of side effects. More than 1g of vitamin C, for instance, can cause diarrhoea. Too much iron can lead to an upset stomach, nausea, fatigue and joint pain.

Many of us drink juice to get extra nutrients into our diet, increase our energy level and fend off illness. But Susie Rucker, a nutritional therapist at Body With Soul, says drinking too much of the wrong juices and using non-organic produce can be counterproductive. As fruit is high in fructose, a natural sugar, Susie says that drinking too much fruit juice can also lead to unstable blood sugar levels and increase risks of obesity and Type 2 diabetes. To cut down on sugar content, throw in vengetables like kale and cucumber. If you use non-organic produce, peel them to minimise chemicals and pesticides that are commonly found on the skin.

Read your food labels carefully as low-fat foods may be high in sugar. Very often, food manufacturers take out the fat and add sugar to it to boost its taste. Yogurt, cereal, ice cream and many other snack foods that are labelled low-fat, reduced fat or non-fat, tend to have high levels of sugar. A healthy diet should include some fat, so there’s no reason to avoid full-fat products. What’s more, dietary fat is essential for optimal brain function and for processing fat-soluble vitamins A, D, E and K, adds Susie.