The second decade of life is dominated by adolescence, which is the transition from childhood into adulthood. Adolescence is characterised by changes not only in physical development, but in psychological, social and mental development. In fact, the major disorders of adolescence are mental disorders, such as ADHD, eating disorders, and depression. Three times as many girls suffer depression as boys. Boys are more likely to commit suicide, and two-thirds of all adolescent deaths are due to accidents or suicide.
The most common conditions suffered by young people in this age group are headache, asthma, colds, dental problems, hay fever, musculoskeletal problems, sore throats/coughs and skin problems (including eczema and acne). The main reasons this age group goes to the doctor are for respiratory diseases, "female problems", digestive conditions and musculoskeletal conditions.
Following are some of the changes that take place during this exciting period of growth and sexual maturity:
BONES AND TEETH
The bones continue to grow longer and stronger as the cartilage is replaced by bone. Growth of bones stops when all of the cartilage is finally replaced by bone, and by the age of 18 the muscles have become fully developed.
The teeth continue to develop and by the age of 13 the second molars appear, while the third molars - the last of the adult teeth - appear after age 17 years.
HEART AND CIRCULATORY SYSTEM
The heart increases in size due to the increase in size of the heart muscle cells. The heart rate continues to slow down to normal adult rate and reaches an average resting rate of between 60 and 80 beats per minute. The rate is actually slowest in people who are athletic and maintain their physical fitness. As the heart rate decreases, blood pressure increases to adult levels and the volume of blood and the concentration of haemoglobin also increase.
When young girls reach reproductive age, the risk of iron deficiency increases due to blood losses during menstruation. The National Dietary Survey has shown that 10% of 12 - 15 year old girls had iron intakes less than 50% of their recommended intake.
BRAIN AND NERVOUS SYSTEM
The nervous system is fully developed by the age of 18 years. While the brain does not increase significantly in size during adolescence, the size of the skull and facial bones change, and facial features sometimes appear to be out of proportion until full adulthood.
Growing up, dealing with pressures from peers and parents, and coping with study and exams all create stresses on the nervous system. There are a number of nutritional and herbal treatments that can help the individual to cope with stress, and there are supplements specifically formulated to help with study; some herbs have been shown to benefit concentration, comprehension and memory recall.
If it is not dealt with early enough, stress can lead to anxiety and depression- although there are herbs that can help with these conditions, they are potentially serious disorders that need expert diagnosis and treatment.
SKIN AND HAIR
With the onset of adolescence the skin becomes thicker and additional hair growth occurs in both boys and girls. Hormones stimulate the production of sweat and sebum in the skin. Increased sweat gland activity results in perspiration and body odour. The increase in the activity of the sebaceous glands can result in blockages of the glands which can lead to pimples and acne. These blockages are called comedones and may become infected. Skin treatments containing tea tree oil can be an effective way of treating the infection and reducing redness.
THE REPRODUCTIVE SYSTEM
Growth and sexual maturity in the transition from childhood to adulthood are controlled by the endocrine (hormone) system. The growth hormone which regulated growth in childhood is supplemented with sex hormones which initiate the adolescent growth spurt. Gonadotrophic hormones promote the secretion by the ovaries of oestrogen and progesterone, and secretion of androgens by the testes. These hormones are responsible for the development of the primary sex characteristics - the internal and external genitalia- and the secondary sex characteristics (such as pubic and underarm hair) that signal maturity but are not involved in reproduction. These sex hormones regulate the growth spurt by ending skeletal growth.
GROWTH AND ENERGY
The adolescent growth spurt usually lasts between 2 and 3 years. For girls the growth spurt begins from 10-14 years of age and is over by 16 or 17. Girls typically gain 5 to 20cms in height and 7 to 25kgs in weight.
The male growth spurt starts later but can continue up until the age of 18 to 20, although it is possible to increase in height until about 25 years of age. Boys typically gain 10 - 30cms in height and 7 to 30kg in weight.
There is a definite pattern to growth during adolescence. Growth starts first in the arms, legs, hands, feet and neck, followed by an increase in hips and chest, and finishing with shoulders and length of the trunk. In boys the trunk becomes broader while the pelvis remains narrow; in females the opposite occurs.
The larynx and the nasal sinuses grow, resulting in a deeper, more resonant adult voice.
SOME IMPORTANT ISSUES FOR ADOLESCENTS
One of the major issues facing teenagers is to do with weight; overweight due to poor lifestyle management, and underweight due to preoccupation with body image.
Among young adults aged between 12 and 15 years, 5.3 per cent are overweight while a further 10 per cent are at risk. Adolescence is one of three periods in which obesity is associated with persistent adult obesity (the others are infancy and between the ages of 5 and 7).
Eating disorders such as anorexia nervosa and bulimia nervosa are serious disorders that are most common in girls aged 15 or more. Anorexia causes nutritional deprivation and can affect physical growth, can have long-term effects on reproduction and can cause osteoporosis. Bulimia is much more common than anorexia and it results in electrolyte losses which can cause dizziness, weakness, fluid retention. Associated vomiting affects the upper gastrointestinal tract and erodes the teeth.
Anorexia and bulimia are potentially life threatening and need early recognition and prompt attention by a health care professional.
Adolescents need a balanced diet that is high in energy to fuel their rapid growth; they need sufficient exercise for optimal health and to promote bone density. Surveys show that adolescents are exercising less than they once did, and they exercise less as they progress through their teens; they are also eating less good food such as cereals, fruit and vegetables.
It is critical to monitor weight and height during childhood and adolescence to ensure normal development.
A healthy attitude is critical for the next stages of growth; diet and exercise play a role in the later development of many diseases and adolescence is the right time to teach the responsibility of looking after one' own health.
REFERENCES:
- Porth, Carol Mattson. Pathophysiology. 5th Edition 1998, Lippincott-Raven
- Roy Morgan Research, 2002
- Wahlqvist, M. Food and Nutrition in Australia. Allen and Unwin 2nd Edition 2002
- Complete Home Medical Guide. Dorling Kindersley 2001
- Australia’s Health 2000. Australian Institute of Health and Welfare
- Healey, Kaye. The food we eat. Vol 83 Spinney Press 1997
