"The danger of chronic stress is that people get used to it after a while and just ignore it. Or they may not know that they are experiencing stress at all," says psychologist Daniel Koh from Insights Mind Centre in Singapore. "This can lead to health problems accumulating or showing up suddenly."

Some of the more serious dangers associated with chronic stress include high blood pressure, stroke and heart disease, caused by the narrowing of the arteries and elevated cholesterol levels, says Koh. Caregivers may also take to drinking and smoking to cope with their stress, which leads to more illnesses.

"Early-stage research also indicates that stress is linked to cancer because stress weakens the immune system," he points out. "When a person's immune system is compromised health problems tend to develop at a faster rate and healing takes longer than usual."

Koh suggests getting help from others, resolving issues rather than avoiding them, finding time for rest and relaxation, working within your limits and abilities and having a life outside your job.

Security guards and nurses should take note. One of the main problems associated with shift work is sleep deprivation. Chronic sleep deprivation is associated with obesity and type 2 diabetes. But according to a study published in in November, night shift work may also increase one's risk of developing breast, prostate, colorectal and endometrial cancers. In fact, the International Agency for Research on Cancer goes so far as to say that shift work involving circadian (daily) rhythm disruption likely causes cancer.

How this happens is unclear and more research is needed, but the risk appears related to circadian rhythm disruption and the complex interactions of melatonin secretion, immune dysfunction, sleep deficiency and metabolic imbalances.

Melatonin is a powerful hormone that is normally produced at night and suppressed by ambient light. It regulates reproductive hormones, particularly oestrogen, reduces oxidative damage and boosts production of other antioxidants.

Recent research published in found that working night shifts might increase the risk of developing ovarian cancer. More than 3,000 women, with either the most common type (epithelial) of advanced ovarian cancer, borderline disease, or with no ovarian cancer, were studied.

Working night shifts was associated with a 24 per cent increase in the risk of developing advanced cancer and a 49 per cent increase in the risk of developing early stage disease, compared with those who worked normal office hours.

Dr Lim Li Ling, medical director at the Singapore Neurology & Sleep Centre adds that a lack of sleep stresses the body, impairing its ability to heal and repair itself when it should. Chronic sleep deprivation can also lead to high blood pressure, heightening your risk of developing cardiovascular disease and stroke.

if working fewer graveyard shifts or using forward-rotating shifts is not an option, Dr Lim says that lifestyle changes are in order. On your off days, make sure you get the maximum amount of sleep, even if it means sacrificing personal time with your family and friends during the day. And to make your bedroom conducive to sleep when it's bright outside, keep the curtains drawn and the room quiet.

Dr John Yu, specialist in dermatology at Dermacare Central, says that construction workers who handle cement and epoxy are at risk of developing skin allergies. Cement contains potassium dichromate, which is harmful. Using cement commonly causes contact rashes. Epoxy, used in adhesives, paint, composite materials, plastic and electrical cables, can cause facial and neck rashes.

Constant, long-term exposure to noisy machinery can affect the eardrum, adds Dr David Ho, a specialist in otorhinolaryngology at Matilda International Hospital.

"Exposure to 80 decibels for eight hours a day can put one at risk of hearing loss and tinnitus. Increase that and for every three extra decibels you get the same amount of damage in half the number of hours. So your risk is the same if you're exposed to 83 decibels for four hours a day, or 86 decibels for two hours a day."

There is also the problem of toxic inhalation. Chemicals in certain construction products can kill nerve endings, affecting the sense of smell. "Although the risk of developing cancer is minimal compared to a smoker, respiratory illnesses are a possibility, in particular, sinusitis, the inflammation of the nasal passages and irritation to the mouth and lungs," Ho comments.

barrier protection is crucial for all construction workers - wearing special suits, gloves, masks and shoes will minimise direct contact with harmful chemicals and earmuffs buffer the noise. Ho also advises an annual hearing test.

Researchers in Canada recently found that some jobs, such as the manufacturing of car plastics, may increase workers' risk of developing breast cancer. In fact, the study, published in November 2012 in , revealed that women who work in automotive plastics manufacturing jobs were three times more likely to develop premenopausal breast cancer than other women with other risk factors such as family history, weight and smoking history also taken into consideration.

Exposure to potentially carcinogenic vapours is believed to be responsible, with bisphenol A (BPA) thought to be a major culprit. Found in plastic products, this synthetic organic compound leaches out during the manufacturing process.

BPA is thought to be an endocrine disruptor, interfering with hormone production, including oestrogen. BPA can mimic oestrogen in the body, entering cells and causing breast cancer cells to multiply. Women working in food canning and metalworking jobs were also found to be at high risk.

switching jobs may not be possible, but you can minimise other breast cancer risk factors by maintaining a healthy weight, giving up smoking, limiting your alcohol intake, exercising regularly, getting sufficient sleep, and eating foods that have not been processed. It might also help to speak to your supervisors about implementing safer work practices.

Yu points out that working with bleaches and other cleaning agents can damage and burn the skin. In the long term, direct contact can affect the organs and can cause kidney damage, as the chemicals have to be eliminated by the body. In extreme cases, exposure to these chemicals can cause infertility.

It can be difficult to know exactly what chemicals are in various industrial cleaning products, especially since the industry is not as well regulated as it should be, Ho says. It is best to avoid direct contact with these products. Inhalation of chemical cleaners can harm the respiratory system and exacerbate existing health problems such as asthma.

Some signs of infection and inflammation caused by toxic inhalation include a blocked or bleeding nose, pain behind the forehead, eyes or cheeks, or sinusitis. If these symptoms do not clear up within a week, seek medical help.

like construction workers, Yu advises wearing gloves and masks when handling cleaning products. If possible, ensure the area you are cleaning is properly ventilated to prevent the inhalation of any chemical fumes.

Sitting at a desk all day has been linked to obesity and poor blood circulation. However, being on your feet for extended periods can also have a detrimental effect on the body, according to Dr Tommy Ng, an orthopaedic surgeon from the Hong Kong Orthopaedic & Spine Centre.

Teachers, retail workers, assembly line workers, cashiers, waiting staff, and cooks may be more prone to knee stress and lower back pain. Bank tellers and hotel reception staff who look at computers all day may experience anterior neck pain as a result of stress on the scalene muscles that run from the ribs to the sides of the neck.

Prolonged standing can also aggravate existing problems such as arthritis, muscle strain, poor blood circulation in the legs and plantar fasciitis.

To cope with the stress on the joints, you may slouch or shift your weight from one leg to another, but this is bad for your posture.

Some of the more serious health issues associated with prolonged standing includes arthritis in the knees and hips, high blood pressure and permanent damage to some muscles.

Ng suggests maintaining good posture throughout the day. Correct your position when you find yourself slouching. You can also do on-the-spot exercises like ankle and shoulder rotations to keep the blood flow going, and don't forget to go for short walks while you're on a break.