There were 865 deaths with heart disease listed as the underlying cause reported in Texas during the week ending November 20, a 1.6 percent increase over the previous week, according to The Centers for Disease Control and Prevention.

In the week ending November 20, there were 4,321 deaths in the state. 20 percent of deaths were caused by heart disease, 18.4 percent were from cancer and 16.5 percent were from COVID-19. Additionally, 9.7 percent of deaths were from Alzheimer's disease and dementia.

Studies show doctors and medical examiners may underreport Alzheimer's disease and dementia-related conditions as the underlying cause of death on death certificates, according to the National Institute on Aging.

Once infected, older adults with dementia are likely to develop a more severe and dangerous illness. The diseases which make an older adult more vulnerable to COVID-19 are age-associated chronic conditions, according to the Bright Focus Foundation.