Our circulatory system, including our heart and lungs, pumps blood around our entire body more than 1000 times a day.

It's easy to think of this system as a simple structure that joins the heart and lungs to take oxygenated blood and nutrients through the body and cart it back again. But the truth is it's much more complex. Poor circulation, regularly experienced as cold hands and feet, may be a warning sign that your circulatory system's not too flash.

Cold hands, warm heart

If you find that your colleagues turn on the air conditioning but you have to turn it off because your hands and feet feel cold even on the warmest days, you're not alone. This sensitivity is experienced by many women, particularly those under the age of 25. Caused by a reaction to a drop in temperature, the skin's blood vessels decrease their size to shunt blood to the organs.

Vasoconstriction, as it's known, is more common in slim people because body fat is naturally warming. Smokers may also regularly experience it, because smoking lowers the oxygen content in the blood, contributing to a lack of sensation in the hands and feet. Vasoconstriction can also occur when you're stressed because hormones affect nerve endings much like temperature does.

More than cold fingers

The symptoms of vasoconstriction can be troublesome. As well as fingers and toes, the nose, ears, tongue and even the nipples of breastfeeding mothers can be affected. This extreme sensitivity is known as primary Raynaud's phenomenon. It's thought to be genetic. An Australian study found that one in five women experience it at least once in their lives. As the temperature dips, changes in skin colour - from pink to blue to white - may occur as the blood supply diminishes. When blood flow returns, the skin turns from blue to red and finally back to pink.

The big freeze

Secondary Raynaud's phenomenon is more disabling and mainly affects women with an autoimmune disease. These are conditions where the body's defence system becomes chaotic and turns on itself.

Autoimmune diseases such as scleroderma or lupus affect the connective tissue through which thermo-regulating blood vessels run. Therefore the reaction to temperature change is severe because the ability of the blood vessels to work effectively may be destroyed. The reaction can cause skin ulcers and upset the use of hands and feet. However, the changes are usually short term and eventually the reactions stop.

Quick tips to help end an attack - fast!

The trick during an attack of cold hands and feet is to get warm as quickly as possible:

Soak your hands or feet in warm (but not hot) water.

Put your hands under your armpits for greater warmth.

Circle your arms around like windmills to send blood to your fingers.

When poor circulation is harmful

Poor circulation can be life-threatening, especially atherosclerosis, a build-up of unhealthy fatty deposits in the arteries that leads to a decrease in blood flow. This can result in stroke or heart attack. Follow these measures to combat poor circulation:

Improve the flow

To help protect yourself from the cold:

• Wear gloves, socks and a hat if it's chilly.
• If you have Raynaud's (see above) wear gloves and socks with medical-grade silver wool, which reflects 95 per cent of body heat back into the skin.
• Take a jumper to the movies because air conditioning can bring on a reaction.
• Protect your hands when getting food out of the freezer.

Quit smoking

Many of the 5000 chemicals in a single cigarette cause blood vessel constriction.

Take care with medication

Pseudoephedrine, often found in cold and flu medications, constricts blood vessels. Migraine medications containing ergotamine and herbal potions that contain ephedra have the same effect.

Manage stress

Identify what stresses you out and try to avoid these triggers where possible.

Stride with pride

There's evidence that brisk walking for 20 to 30 minutes a day improves circulation.

Watch what you eat

To help improve your blood flow:

• Eat five serves of vegies, two serves of fresh fruit and some lean meat (or beans or tofu) each day to combat weight gain and prevent clogged arteries.
• Eat fish such as tuna, sardines and salmon three times a week to benefit from the
  omega-3 fatty acids. Take fish-oil tablets if you don't like eating fish.
• Walnuts also provide omega-3.
• Cut back on drinking tea and coffee. Wearing socks can ease the effects of poor circulation

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