Description: One of the clear signs of #illness, regardless of age, is a sudden and drastic change in #behavior or mood. This can often indicate that something is wrong physiologically, and it is important to take notice and seek medical attention. In both children and older adults, a weakened immune system can often be a sign of underlying illness. Frequent or recurring illnesses, such as infections or colds, should not be ignored, as they may indicate a more serious health issue that needs to be addressed. Unexplained weight loss or gain can also be a concerning sign of illness in individuals of #all-ages. Sudden weight loss without any changes in diet or exercise can indicate serious health conditions, while unexplained weight gain may be a sign of hormonal imbalances or other medical issues that require evaluation by a healthcare professional.