They may also present as brief but distracting or painful interruptions in normal breathing, with sudden momentary pain of the throat, chest, or abdomen. Causes
Pathophysiological causes
Swallowing air excessively
Gastroesophageal reflux
Hiatal hernia
Rapid eating
Carbonated beverages, alcohol, dry breads, and some spicy foods
Opiate drug use
Laughing vigorously or for a long timeHiccups may be triggered by a number of common human conditions. In rare cases, they can be a sign of serious medical problems. In rare cases, hiccups can be the sole symptom of myocardial infarction. Pre-phrenic nucleus irritation of medulla
Kidney failure

CNS disorders
Stroke
Multiple sclerosis
Meningitis

Nerve damage
Damage to the vagus nerve after surgery

Other known associations
Although no clear pathophysiological mechanism has been described, hiccups is known to have been the initial symptom of Plasmodium vivax malaria in at least one documented case. Evolutionary theories
The burping reflex hypothesis
A leading hypothesis is that hiccups evolved to facilitate greater milk consumption in young mammals. The coordination of breathing and swallowing during suckling is a complicated process. Some air inevitably enters the stomach, occupying space that could otherwise be optimally used for calorie rich milk.The hypothesis suggests that the presence of an air bubble in the stomach stimulates the sensory (afferent) limb of the reflex through receptors in the stomach, esophagus and along the underside of the diaphragm. This triggers the active part of the hiccup (efferent limb), sharply contracting the muscles of breathing and relaxing the muscles of the esophagus, then closing the vocal cords to prevent air from entering the lungs. This creates suction in the chest, pulling air from the stomach up into the esophagus.
They recommended that complementary policies are necessary to ensure economic growths positive impact on LDC employment. With trade, industry and investment, they only found limited evidence of positive impact on employment from industrial and investment policies and for others, while large bodies of evidence does exist, the exact impact remains contested.Researchers have also explored the relationship between employment and illicit activities. Using evidence from Africa, a research team found that a program for Liberian ex-fighters reduced work hours on illicit activities. The employment program also reduced interest in mercenary work in nearby wars. The study concludes that while the use of capital inputs or cash payments for peaceful work created a reduction in illicit activities, the impact of training alone is rather low. Globalization and employment relations
The balance of economic efficiency and social equity is the ultimate debate in the field of employment relations. By meeting the needs of the employer; generating profits to establish and maintain economic efficiency; whilst maintaining a balance with the employee and creating social equity that benefits the worker so that he/she can fund and enjoy healthy living; proves to be a continuous revolving issue in westernized societies.Globalization has affected these issues by creating certain economic factors that disallow or allow various employment issues. Economist Edward Lee (1996) studies the effects of globalization and summarizes the four major points of concern that affect employment relations:

International competition, from the newly industrialized countries, will cause unemployment growth and increased wage disparity for unskilled workers in industrialized countries.