A qualified healthcare provider should be consulted before making decisions about therapies and/or health conditions.

Patients who suddenly incorporate large amounts of fiber into their diet may experience some bloating and diarrhea.

High blood pressure is a dangerous condition because the physical changes that may result in a heart attack, stroke, or kidney failure take many years to develop. Because the changes are slow and the symptoms are not obvious without a visit to the doctor, many people do not know how serious high blood pressure can be until they or a loved one experiences a medical emergency.

A patient's blood pressure is recorded as a fraction. The numerator (top number of the fraction) is higher than the denominator (bottom number of the fraction). A person's blood pressure is considered high if the systolic pressure (top number of the fraction) is above 140 and if the diastolic pressure (bottom number of the fraction) is above 90. Patients with blood pressure that is just below these numbers are defined as prehypertensive and should also take steps to lower their blood pressure.

The emphasis on the range of foods that are permitted in the DASH diet is designed to appeal to hypertensive patients who normally are instructed primarily about food restrictions. Experts believe that the focus on abundance rather than adhering to rules will help make individuals more likely to follow the DASH diet plan.

The DASH diet was based in part from data about the lower incidence of certain health problems experienced by vegetarians. It has been found that vegetarians tend to have a lower risk of suffering a stroke, heart attack, or kidney failure due to high blood pressure because individuals who follow a vegetarian diet tend to have lower than average blood pressure. A vegetarian diet also tends to be higher in unsaturated fat, fiber, calcium, potassium, and magnesium than other diets.

Individuals who eat mostly processed foods generally consume too much sodium and not enough potassium, calcium, and magnesium present in foods such as low fat dairy products, vegetables, and fruits. Most prepackaged foods that contain sauce or flavoring packets, pre-mixed ingredients, pre-cooked meats, or pre-cooked meats that are already sliced, diced, or deep fried are considered processed.

Researchers have found that taking calcium, potassium, and magnesium supplements without reducing the amount of processed food in the diet does not help lower blood pressure or reduce the likelihood of heart attack or stroke.

A 2006 trial by Elmer et al. evaluated several behavioral interventions to lower blood pressure and improve lifestyle behaviors of patients with high blood pressure. The length of the trial was six months. Patients who followed the DASH diet showed a statistically significant reduction in weight and sodium and fat intake. In addition, these individuals also statistically increased their intakes of minerals, fiber, dairy, fruits, and vegetables. The authors concluded that patients who undergo and sustain multiple lifestyle modifications, such as those required by the DASH diet, improve their blood pressure readings and may reduce their risk for chronic disease.