Hi welcome to HCM Sudden drop in BP has many possible causes, from lifestyle choices, to medication or an underlying health condition. Sudden fall in blood pressure also can be dangerous and can cause dizziness and fainting when the brain fails to receive an adequate supply of blood. Even mild dehydration can cause weakness, dizziness and fatigue . A lack of the vitamins B-12 cause a condition in which your body doesn t produce enough red blood cells , causing low blood pressure. Drink more water. Alcohol is dehydrating and can lower blood pressure . Water, on the other hand, combats dehydration and increases blood volume. Follow a healthy diet. Get all the nutrients you need for good health by focusing on a variety of foods, including whole grains, fruits, vegetables, and lean chicken and fish. Use more salt but if you don t like a lot of salt on your food, try using natural soy sauce or adding dry soup mixes to dips and dressings. Go slowly when changing body positions. You may be able to reduce the dizziness and lightheadedness that occur with low blood pressure on standing by taking it easy when you move from a prone to a standing position. Before getting out of bed in the morning, breathe deeply for a few minutes and then slowly sit up before standing. Sleeping with the head of your bed slightly elevated also can help fight the effects of gravity. If you begin to get symptoms while standing, cross your thighs in a scissors fashion and squeeze, or put one foot on a ledge or chair and lean as far forward as possible. These maneuvers encourage blood to flow from your legs to your heart. Practise swift walk , jogging , Deep Breathing Inhale - Hold - Exhale - Hold , Kapalbhati , Bhramari Omkarnad with a traned guide . Eat small, low-carb meals. To help prevent blood pressure from dropping sharply after meals, eat small portions several times a day Take a cup of hot milk with a spoon of honey and almond oil at bed time . and any time you feel low . A palm full of nuts twice a day also help . Your doctor also may recommend drinking coffee or tea with meals to temporarily raise blood pressure. But because caffeine can cause other problems, check with your doctor before drinking more caffeinated beverages. Hope this helps solves your query .Take care , All the best . Don t hesitate to get back if have any further query