Monday 19 March 2018

I wake up in the middle of the night with numb hands

Hand numbness
Hand numbness

Nina Byrnes

Our GP on how to combat hand numbness and what causes fingernails and toenails to be hard or soft.

Q. For the past couple of years, I have been waking up in the middle of the night with numbness in my hands. It never effects the whole hand, just the last two fingers on each hand. I have a feeling it might be connected to a tightness in my shoulders, as I often get headaches from extremely tight muscles between my shoulder blades. I sit at a desk but I am very conscious of posture, taking breaks and stretching out my muscles. Can tight muscles cause numbness, or could this be a sign of something more serious? Is this something I need to get checked out?

Dr Nina replies: The ulnar nerve is one of the three main nerves in the arm. It exits from the brain at the neck and travels a long path down the arm. At the elbow, it passes through a tunnel of tissue called the cubital tunnel that runs under a bump of bone ( the medial epicondyle) at the inside of the elbow.

The nerve lies very close to the skin here and bumping off it causes a shock-like feeling. The spot where the nerve runs under the medial epicondyle is commonly referred to as the 'funny bone'.

Constriction can occur in several places along the ulnar nerve's path from the neck to the hand. The most common place for compression is behind the inside part of the elbow. Ulnar nerve compression here is called 'cubital tunnel syndrome'.

The ulnar nerve provides feeling to the little finger and half of the ring finger. It controls most of the little muscles in the hand that help with fine movements, and some of the bigger muscles in the forearm.

There are several things that can cause ulnar nerve compression. Bending the elbow stretches the ulnar nerve at the medial epicondyle. This can irritate the nerve. Keeping the elbow bent for long periods or repeatedly bending your elbow can cause painful symptoms.

Those who sleep with their elbow bent may be prone to symptoms, often waking with their hand numb or weak. Leaning on the elbow for prolonged periods of time can put pressure on the nerve, leading to symptoms.

Fluid collections in the elbow, such as those that occur with bursitis or injury, can cause swelling leading to symptoms. A direct injury or hit to the inside of the elbow can cause pain, electric-shock sensation, and numbness in the little and ring fingers. This is often referred to as hitting the 'funny bone'.

Those who have injured their elbow in the past, who have arthritis or swelling of the elbow, or who lean on their elbows a lot are most at risk.

Numbness of the little and ring finger is the most common symptom of cubital tunnel syndrome. This initially comes and goes. As nerve damage progresses, there may be weakness of the muscles or eventually muscle wasting.

In order to avoid symptoms, ensure good posture and positioning at a desk. Don't rest your elbow on the arm rest of chairs or the window of cars. If you have stiff muscles in your neck or shoulders, some physiotherapy or massage may release spasm there and further down the arm. A physiotherapist will be able to assess all the muscles, or the neck and arms, and this is always a good place to start.

If symptoms are progressing or persist, it is important to see your doctor. They may prescribe anti-inflammatory medication. Local steroid injections can help in some cases.

If symptoms are severe or there is muscle weakness or damage, referral to a neurologist for nerve studies may be warranted. Splinting may be recommended to allow the nerve to settle. Surgery is thankfully only rarely required. This can be done to release the nerve from the narrow tunnel and it can be an effective treatment in certain cases. If symptoms have been there several years, a visit to the GP is warranted.

Q. What causes fingernails and toenails to be hard or soft and is there any supplement that improves nail quality?

Dr Nina replies: Two of the most common causes of brittle nails  are prolonged exposure to water or overuse of nail polish. The first may be an occupational hazard. If you wash your hands regularly for work, you should apply hand cream frequently throughout the day. Breaking the nail polish habit and allowing nails to heal and grow naturally may help improve the second.

Fungal infections are the most common cause of nail infections. These are more common in toenails but may occur in any. Fungal infections may cause thickening, crumbling and splitting of the nails.

An under or overactive thyroid may cause nails to become brittle and crack. Psoriasis may cause brittle, crumbling nails. It may also cause the nails to appear yellow. Brittle nails may also be associated with other inflammatory arthritis.

In anaemia, the nail may become spoon-shaped and seem thinner or more brittle. Transverse lines across the nail can be a sign of recent ill health or injury and may occur during chemotherapy. Whitening of the nails may be due to malnutrition but can also occur in a number of diseases, including diabetes, liver disease and kidney or heart failure.

The appearance of small pits on the nail surface may suggest psoriasis, other inflammatory conditions or eczema.

If you have brittle nails, clean them gently with a soft brush. Cut straight across. Wear protective gloves when washing dishes or using cleaning agents. Moisturise your hands regularly. Using a nail hardener may help protect nails.

There are some suggestions that taking a biotin supplement can help improve nails. However, biotin is readily available in a wide variety of foods and so, it is unlikely that those who eat well would be deficient and require supplements.

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