Being rammed from behind in a car is the classic cause of a whiplash injury (although it can also occur during strenuous sports). About one in five people involved in such a collision ends up with problems of the neck and surrounding area.

The sudden impact pushes your car forwards. After a brief delay, your body follows. Your shoulders move forwards until they're under your head. Then, while your head tilts slightly down towards the steering wheel, your neck extends forwards. When you brake hard, the car stops suddenly, throwing your extending and neck back until they hit the headrest.

This stretches and tears the soft tissues of the neck - the tendons, ligaments and muscles - and may damage the nerves and other structures in the area. This soft tissue damage is known as a whiplash injury, or cervical sprain or hyperextension injury.

Symptoms vary

Symptoms of whiplash usually develop within hours, but their nature can vary enormously.

Typical symptoms include:

• Pain and stiffness of the neck, extending up to the head and down to the shoulders
• Headache
• Numbness or tingling in the arms going down into the hands
• Low back pain
• Dizziness
• Mental problems, such as poor concentration, memory or mental performance
• Tiredness
• Ringing in the ears or tinnitus
• Blurred vision

Most people recover in a matter of a few weeks, but for a few it can be the start of years of trouble.

Key to treatment

The standard treatment used to be to encase the neck in a supportive collar to prevent movement.

These days it's thought better to use a soft collar for a short period and to gently encourage movement of the neck after 24 hours.

The standard approach to all injuries of the soft tissues should be followed:

• Apply an ice pack immediately to reduce swelling
• Take regular pain relief using non-steroidal anti-inflammatory drugs (aspirin or ibuprofen)
• Initial rest should soon give way to a gentle increase in movement, but don't overdo it - your local gym or GP can suggest suitable exercises

Other treatments that may help include massage, traction, ultrasound and physical treatments. A physiotherapist, osteopath or chiropractor can advise you.

Whiplash syndrome

Like any severe soft tissue damage, the pain and other symptoms can take several weeks to fully settle. However a few people have ongoing problem including headaches, stiffness, tingling and other sensations in the arms or legs, tiredness, poor sleep and low mood.

This is referred to as Whiplash syndrome and is similar in nature to other conditions where pain and other symptoms develop as a result of damage to the nerves (called neuropathic pain). Treatment from a pain specialist may be needed.

If your symptoms don't start to settle within a few days, it may be worth seeing your doctor for further advice.

If you have any symptoms that you find particularly worrying, see your doctor sooner rather than later.

This article was last medically reviewed by Dr Trisha Macnair in September 2008