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.
But if your thyroid produces too much, it can cause anxiety symptoms, such as nervousness, irritability, heart palpitations, and sleeplessness. If you have anxiety symptoms along with swelling in your neck, weight loss, weakness, fatigue, or heat intolerance, ask your doctor to check your thyroid gland.