Anxiety can often make these related conditions worse, so talk with a mental health care professional if anxiety begins to interfere on a daily basis.
In probability theory and statistics, the variance of a random variable is a measure of its statistical dispersion, indicating how far from the expected value its values typically are. The variance of a real-valued random variable is its second central moment, and it also happens to be its second cumulant.
Variance is the average of the squared deviations from the arithmetic mean. The standard deviation is a square root from variance value. The standard deviation is a measure of the variability of values around the mean and is meant to be used with values that are normally distributed (e.g., follow a normal curve).