WHETHER YOU'RE a boundary-pushing 20-year-old, a career-driven thirty-something, a financially secure 40-year-old, or fit, fabulous and 50, each decade of life brings different health conditions and problems. Lifestyle, work habits, peer pressure, and family and social expectations are all contributing factors, but don't despair: it's not too late to safeguard your wellbeing at any age. Here, health and medical experts outline what to be aware of - and how to deal with it - from your 20s to your 50s. In your 20s Although this is a forgiving decade, you can't get away with an unhealthy lifestyle forever. Take steps now to prevent disease - particularly heredity conditions - from developing later. 'Become aware of any potential health problems,' says naturopath David Stelfox. 'Adopt a lifestyle, exercise and dietary approach that will help minimise health risks.' There's no warning, for instance, that a diet is deficient in calcium, says Henry Donald, an osteopath at Hong Kong's Vitality Centre. Osteoporosis becomes apparent later in life because of an insufficient intake of calcium earlier. Fortunately it's not too late to take action. You have until about 25 to make your bones as dense as possible. Donald recommends eating calcium-rich foods such as low-fat dairy products and including supplements of about 800-1,000mg of calcium a day. 'Keeping active through weight-bearing exercises such as jogging, brisk walking, tennis, aerobics and tai chi will build up peak bone mass,' Donald says. The effects of smoking such as lung cancer and heart disease may mean nothing in your 20s, but problems often arise in the decades ahead. Late nights, alcohol, smoking and drugs take their toll on the body and mind, says Stelfox. 'Moderation and compensation for these excesses is important,' he says. Good nutrition and adequate sleep are vital to counter the effects of an overactive social life. Sexually transmitted diseases, unplanned pregnancies and terminations are common, often-neglected health concerns in this age group. 'Sexually active women should have regular pap tests [once every two years] to allow early detection of any abnormalities, cervical cancer and STDs,' says Grace Wong Ching-yin, a senior doctor at the Family Planning Association of Hong Kong. Unchecked, there's a risk of infertility or pregnancy complications later. 'Physically speaking, we're in our prime [in our 20s], says David Menhennett, fitness supervisor at Pure Fitness, Central. 'Never again will we have the potential to be fitter and stronger. The biggest concern is that we assume our bodies will look after themselves.' And that's just not the case, says general practitioner Sue Jamieson. 'The younger body copes with this physical testing well. But it's here that the seeds of future problems are sown,' she says. 'That ankle sprain which isn't treated properly and given rest heals with [scar tissue]. The 20-year-old pushes on ignoring minor pains. But often these injuries will come back to haunt us at 40, with stiffness, lack of mobility and arthritis.' In your 30s Women at this age tend to be financially secure enough to start a family, but pregnancy difficulties can arise. 'It may take longer to conceive than for a younger woman because [women in their 30s] ovulate less frequently,' says Richard Schwarz, vice-chairman of obstetrics and gynaecology at Maimonides Medical Centre in New York. 'Fertility tends to decrease slowly after 30, and your chances increase of giving birth to a child with Down Syndrome or another chromosomal defect. Women in this age group are more likely to suffer a miscarriage.' Although it's important to be aware of the risks, Schwarz says most of the potential problems can be remedied. Most women aged 35 or over have healthy babies. He recommends a preconception check-up, early and regular prenatal care, conceiving when you're a healthy weight, eating foods rich in folic acid (leafy greens, whole grains, beans), and avoiding smoking, second-hand smoke, alcohol and over-the-counter medications. Stellfox says juggling family and work commitments without any release can take a toll. Accepting as normal chronic stress-related symptoms such as headaches, panic attacks and insomnia is dangerous. He says dietary advice and herbal treatments may help those seeking natural alternatives. Relaxation through meditation or yoga - or simply making time that's your own is essential. As well, the metabolic rate begins to slow during this decade. Now is the time to adopt a balanced diet: ditch fatty snacks, calorie-laden fast food and quick cafeteria lunches. Opt for more frequent home-cooked meals. 'Less time for exercise starts to become a concern as people are focused on starting a family or putting in more time at work,' says Menhennett. But working out can help relieve stress. In your 40s 'Poor choices in diet, insufficient exercise, and irresponsible consumption of drugs and alcohol during the previous 20 years will have weakened and damaged the organs and their associated functions,' says Stelfox. Although health problems that are common in this decade - such as cardiovascular diseases and arthritis - may not be reversible, their severity can be moderated with medication and therapy. Hereditary factors also become apparent in the 40s, says Jamieson. 'Blood pressure and cholesterol rise with age - more so if there's a family history.' Thyroid problems can also occur during this time because of changes in the metabolism. 'Unfortunately, this is notoriously hard to pick in blood tests, which have a very wide normal range,' he says. 'Discussing symptoms such as skin, hair, body temperature changes and weight gain with your doctor is often more fruitful than blood tests.' Health checks for heart disease, diabetes and cancer are essential, says MediNet Health Centre's medical director Francois Fong. 'For women, breast cancer risk increases, so regular mammograms become even more important.' And cut back on alcohol. More than four standard drinks a day may increase the risk of tumours. Men in their 40s have an increased risk of cardiovascular disease due to stress, Fong says. In Hong Kong alone, an estimated 290,000 women and 100,000 men suffer from osteoporosis, says Wong. A bone-density test is an effective way to detect weakness and calcium deficiency. Joint stiffness and reduced flexibility are telltale signs of inactivity, and are common at this age. Yoga, Pilates and tai chi can do wonders to restore movement and suppleness, says Fitness First trainer Richard Hung. In your 50s Although some people may slow down during this decade, it's not the time to go easy on a healthy diet and exercise. Maintaining these positive habits will ensure graceful ageing. Stelfox says conditions such as Alzheimer's appear to be more prevalent now. 'Links have been established with poor nutrition, toxins and mental laziness,' he says. Although Alzheimer's is the most common form of dementia and its effects are irreversible, vascular dementia (caused by high blood pressure and mini-strokes) can be prevented by following a healthy diet, cutting back on salt and fat, exercising regularly, and combating stress through relaxation. Be sure to have your blood pressure and blood-fat levels tested yearly. Women experience menopause between the ages of 45 and 55. 'Menstruation becomes irregular and changes will persist until menstruation stops completely,' says Wong. 'When a woman hasn't menstruated for more than a year she's considered to have reached menopause.' The accompanying reduction in oestrogen levels results in physiological and psychological changes, including hot flushes, vaginal dryness, osteoporosis, coronary and arterial changes and mood swings. Poor self-image is a common grievance. 'Menopause is not a sign of old age - it's the beginning of a new phase of life,' says Wong. 'Women should set fresh goals, develop new interests and learn new skills.' Men aren't without their own problems. Erectile dysfunction is a common condition. An estimated 10 per cent of men are affected, says Wong. 'Erectile dysfunction can be an early symptom of underlying medical conditions. It's essential for men with such a problem to seek early diagnosis and treatment.'