I believe they mean that the random variables have a common support. For example, if X ~ Unif[0,2] and Y ~ Unif[1,3], then their respective PDF's overlap in the interval [1,2], meaning the only interval where both X and Y can have common values is [1,2]. To illustrate, below is a representation of the supports of X and Y, below which is a representation of the real line.
1 Thyroid cancer is a malignant tumor of the thyroid gland. 2  Symptoms of thyroid cancer include swelling in the neck (goiter), neck pain, hoarseness, swallowing and breathing problem, swollen lymph gland in the neck.
Thyroiditis. Thyroiditis can cause temporary hyperthyroidism followed by hypothyroidism. It is an inflammation of the thyroid gland, which may cause tenderness or pain to the neck, jaw or ears. Viruses, fever, medication, pregnancy or immune disorders may cause thyroidtitis, though often the cause is unknown.arge goiters, seen or felt at the base of the neck, may cause tightness in the throat, hoarseness, and difficulty breathing or swallowing. A swollen thyroid can increase or decrease the production of thyroid hormone and can present additional symptoms.