According to Master of Science, Doctor Le Thi Hong Tham, from the Respiratory Department, Tam Anh General Hospital Hanoi, certain abnormalities in the hands can signal underlying lung issues.

**Bluish Fingertips**

Bluish discoloration of the fingertips signals a lack of oxygen in the blood. This occurs when hemoglobin, the oxygen-carrying protein in red blood cells, has low oxygen saturation. Oxygen-deficient blood circulating to the extremities causes the skin to change color.

If this condition persists or recurs frequently, an early lung function check is necessary. It often indicates chronic obstructive pulmonary disease (COPD), severe asthma, or respiratory failure.

When experiencing bluish fingertips or persistent dermatitis, patients should seek early medical attention. Image created by AI.

**Clubbed Fingers**

Clubbed fingers are characterized by enlarged fingertips and downward-curving nails. This results from prolonged oxygen deprivation, which causes soft tissue proliferation around the nails. This manifestation often accompanies dermatological or musculoskeletal abnormalities, or it can appear in isolation.

Clubbed fingers are associated with many conditions, including cardiovascular disease, lung disease, infections, cancer, inflammation, and vascular issues, though they can also be idiopathic or genetic. Even if painless, medical consultation is advised to identify the underlying cause.

**Persistent, Unusual Hand Numbness**

Persistent numbness, tingling, or loss of sensation in the hands points to peripheral nerve damage. In some cases, a lung tumor might compress the brachial plexus, leading to pain, numbness, or weakness radiating down the arm.

If these symptoms persist, do not improve with rest, and are not linked to common causes like vitamin deficiencies or metabolic diseases, patients should seek examination to rule out lung lesions.

**Dermatitis on Hands**

Certain skin lesions, such as pinkish-purple macules or papules on the finger joints or back of the hand, known as Gottron's papules, may be associated with dermatomyositis. Doctor Tham cites research indicating that dermatomyositis is a potential paraneoplastic complication of lung adenocarcinoma. While various other cancers, including ovarian, breast, prostate, kidney, and blood cancers, have been reported in connection, lung and gastrointestinal cancers are the most common.

Tran Duong