When Hormones Go Wrong
The endocrine system keeps the body balanced, but if a gland makes too much or too little of a hormone, coordination is disrupted and disease follows. These disorders show how important a steady hormone level is.
Key idea
Diabetes mellitus happens when the pancreas cannot make enough insulin (or the body cannot use it). Blood sugar stays too high, and glucose appears in the urine.
Some Common Disorders
- Diabetes — too little insulin, so blood sugar is too high.
- Goitre — a swelling of the thyroid, often from a lack of iodine, which the thyroid needs to make thyroxine.
- Gigantism / dwarfism — too much or too little growth hormone from the pituitary during childhood.
- Overactive thyroid — too much thyroxine raises metabolism, causing weight loss and a fast heartbeat.
Drugs and the Nervous System
Coordination can also be disrupted by chemicals that act on the nervous system. Stimulants (such as caffeine and amphetamines) speed up nerve signals, while depressants (such as alcohol) slow them down, blurring vision, slowing reactions and impairing judgement. Drug abuse can permanently damage the brain and nerves, and driving after drinking is dangerous because reaction time is slowed.
Many of these problems can be prevented or well managed. Using iodised salt helps prevent goitre, a balanced diet together with regular exercise lowers the risk of type 2 diabetes, and refusing drugs and heavy alcohol protects the brain and nervous system from lasting harm. Early treatment also keeps many hormone disorders under good control.
Example
A person with untreated diabetes feels very thirsty and tired and passes urine often. A doctor may prescribe insulin injections and a controlled diet to keep blood sugar in a safe range.
Remember
Too little insulin -> diabetes; too little iodine -> goitre. Alcohol is a depressant that slows the nervous system.