Why Your Left Arm May Feel Colder Than Your Right

Why Your Left Arm Feels Colder Than Your Right Arm

Have you ever noticed that your left arm feels chillier than your right? This common phenomenon has a physiological explanation behind it.

Normal Body Temperature

Before understanding temperature differences between arms, it helps to know what’s considered a normal body temperature.

The average normal body temperature is generally accepted as 98.6°F (37°C). However, this refers more to your core body temperature, measured internally.

Normal temperatures in your extremities, like your arms, are lower - typically around 90–93°F (32–34°C). Temperatures under 95°F (35°C) in the arms are normal.

Why Are My Arms Colder Than My Body?

Your arms are farther from your core internal organs than other body parts. As a result, they tend to be slightly cooler than more central areas where blood circulates from the heart, like your chest and abdomen.

The muscles and fat levels also differ between your core and extremities. Leaner areas with less insulation like the arms lose heat more readily.

Left vs Right Arm Temperature Difference

While both arms are usually cooler than your core, you may notice your left arm feels chillier. There are two main reasons for this:

Blood Flow Differences

The major artery supplying blood to your right arm branches directly off the aorta, the main artery leaving the heart. This allows more freshly oxygenated blood to reach the right side.

In contrast, blood flowing to the left arm has to go through more detours from the heart. This slightly reduces the amount of warm blood reaching your left arm at any given time.

Dominant Hand Use

Most people are right-handed, meaning the right arm and hand get used more often for daily tasks. This increased muscle movement generates more heat in the dominant arm.

Constant small motions involved in writing, cooking, sports, and other activities can warm the favored arm. The less active left arm remains cooler by comparison.

Other Factors Affecting Arm Temperature

While blood circulation is the main reason your left arm may feel chillier, other factors can also influence temperatures in your arms:

• Outside temperature - Colder ambient temperatures cool your exposed arms.
• Clothing - Bare arms lose heat faster than covered arms.
• Body position - Gravity draws blood into lower limbs when sitting or standing.
• Arm position - Keeping your left arm immobile may prevent heat generation.
• Injuries - Trauma, fractures, sprains, or bruises affect local blood flow.
• Medical conditions - Various illnesses and chronic health problems can alter circulation.

When Temperature Difference Causes Concern

In most cases, a slightly cooler left arm is normal and no cause for worry. However, see your doctor if you have:

• Severe or persistent coldness in one arm
• Pale, blue, or numbness in the colder arm
• Arm pain, swelling, or loss of strength
• Dizziness, chest pain, or trouble breathing along with arm temperature changes

These can indicate an underlying problem like an arterial blockage, blood clot, nerve injury, or other circulation disorder requiring medical evaluation.

Tips to Warm Up Your Left Arm

To balance out a chillier left arm, try these gentle warming techniques:

• Exercise both arms regularly to increase blood flow.
• Apply warm compresses or take a warm shower to ease arm muscle tension.
• Wear long sleeves when in colder environments.
• Sit or sleep on your left side to take pressure off the left shoulder and improve circulation.
• Practice relaxing the shoulders and deep breathing to maximize blood flow.
• Gently stretch and massage the left arm and shoulder to stimulate blood vessels.
• Avoid crossing your arms which can restrict blood flow.

See a doctor if home remedies don't alleviate persistent coldness or discomfort in one arm.

When to Seek Medical Care

Consult your doctor if you experience any of the following in your left arm specifically:

• Discoloration or pale skin
• Tingling, numbness, or reduced sensation
• Noticeable muscle weakness
• Swollen arm or hands
• Trouble moving your arm or fingers
• Sharp, burning, or aching pain

These types of left arm symptoms may indicate an underlying health issue requiring imaging tests and treatment. Prompt medical care is key for conditions like blood clots, nerve compression, or stroke.

Diagnosing Left vs Right Arm Temperature Differences

Doctors can use several methods to evaluate and diagnose arm temperature variances:

• Patient history - Discussing your symptoms and timeline provides context.
• Physical exam - Feeling the arms for coolness and listening to arteries with a stethoscope.
• Arm temperature comparison - Taking and comparing temperature readings in each arm.
• Imaging - Tests like Doppler ultrasound, CT scans, MRIs, and angiograms to visualize blood vessels and tissues.
• Vascular testing - Specialized tests check arterial blood flow in the arms.

Diagnostic testing helps determine whether the temperature difference stems from normal variation or an underlying medical condition requiring treatment.

When Temperature Changes Warrant an ER Visit

Seek emergency care immediately if you have:

• Sudden severe coldness or numbness on one side of your body
• Arm or leg weakness on just one side
• Face drooping on one side
• Slurred speech or trouble speaking
• Confusion or memory loss
• Severe dizziness or loss of coordination

These types of symptoms, especially if new or sudden in onset, can indicate a stroke or transient ischemic attack (TIA) requiring rapid diagnosis and care to prevent permanent damage.

The Takeaway

It’s common for your non-dominant left arm to feel slightly cooler than your right arm due to anatomical differences in circulation and muscle use. Gentle warming techniques can help balance any temperature discrepancies.

However, seek medical care for severe or worsening coldness, pain, numbness, or arm weakness which may reflect an underlying health condition. Prompt diagnosis is key to determine the cause and provide appropriate treatment.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.