What is the nervous system?

The nervous system is made up of the brain, spinal cord and nerves. It is the body’s communication system that controls much of what your body does. It allows you to do things like walk, speak, swallow, breathe and learn, and controls how your body reacts in an emergency.

Your nervous system is made up of:

• your central nervous system, or CNS, which consists of the brain and spinal cord
• your peripheral nervous system, which consists of nerves that connect your CNS to the rest of your body

Nerves are made up of cells called neurons. These carry messages from one part of the body to another. Different types of neurons do different things. For example, some carry messages from the brain to the muscles so you can move. Others detect light and sound and carry information about this to the brain.

What does the nervous system do?

The nervous system is responsible for:

• Intelligence, learning and memory: your thoughts and feelings are controlled by the brain, the control centre of the nervous system.
• Movement: the brain sends messages that control how your body moves.
• Basic body functions: the nervous system controls the things you don’t think about, like the beating of your heart, breathing, digestion, sweating and shivering.
• Responding to an emergency: part of the nervous system called the sympathetic nervous system makes your heart beat faster and causes you to release adrenaline in an emergency.
• The senses: sight, hearing, taste, touch and smell are all controlled by the nervous system.

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What are the common diseases in the nervous system?

There are thousands of conditions that start in or affect the nervous system, including:

• degenerative diseases like Parkinson’s, Alzheimer’s and multiple sclerosis
• stroke
• spinal cord injuries
• seizure disorders, such as epilepsy
• cancer, such as brain tumours
• infections, such as meningitis
• migraines

What are the symptoms of problems with the nervous system?

There are many different symptoms that could suggest a problem with the nervous system. They include:

• headaches
• blurry vision
• fatigue
• behavioural changes
• leg or arm numbness
• loss of coordination
• weakness or loss of muscle strength
• slurred speech
• tremors
• emotional problems
• memory loss

It is important to seek medical help if you have symptoms like these that don’t go away on their own.