Raynaud's syndrome

It can be a co-morbid illness with several other chronic illnesses, including chronic fatigue syndrome, fibromyalgia, lupus, rheumatoid arthritis, and Sjogren's syndrome.<ref.https://www.verywell.com/raynauds-syndrome-chronic-fatigue-716185

Raynaud's Syndrome "is a rare disorder that affects the arteries. Arteries are blood vessels that carry blood from your heart to different parts of your body."

Types

 * Primary is more common and less severe.
 * Secondary is caused by an underlying disease, condition or other factor.

Risk factors
The risk factors for primary Raynaud's (Raynaud's disease) and secondary Raynaud's (Raynaud's phenomenon) are different.

Triggers and symptoms
Cold temperatures can bring on an attack. "During an attack, little or no blood flows to affected body parts. As a result, the skin may turn white and then blue for a short time. As blood flow returns, the affected areas may turn red and throb, tingle, burn, or feel numb."

Tests and diagnosis
"To distinguish between primary and secondary Raynaud's, your doctor may perform an in-office test called nail fold capillaroscopy. During the test, the doctor examines your nail fold — the skin at the base of your fingernail — under a microscope. Tiny blood vessels (capillaries) near the nail fold that are enlarged or deformed may indicate an underlying disease. However, some secondary diseases can't be detected by this test."

To determine if other conditions are the underlying factor for Raynaud's there are blood tests. Antinuclear antibodies test and Erythrocyte sedimentation rate.

Associations
The Raynaud's Association has a FAQ Page.