It can be all of the above of what Devin posted. People with high levels of bad cholesterol need to pay attention to diet focusing on lots of fiber and adding a fiber supplement can help eliminate what your body wants to naturally absorb. Getting into the practice of some form of meditation helps lower stress and high blood pressure and of course working out.
High blood pressure, or hypertension is caused by a number of factors including smoking tobacco, elevated stress, heredity, obesity, and sedentary lifestyle. Cholesterol (I assume you mean Hypercholesterolemia) is associated with hereditary factors, alcohol abuse, and certain metabolic conditions.
Mostly it is the food you eat which contain of fat and more calories, and not just food but stress, depression, anger are also an effect in high blood pressure if those can be maintained there won't be higher chances of getting high blood and cholestrol.
certain medicines and sugar level , stress etc