Your blood cholesterol level is one of the most significant factors that influences your risk of developing atherosclerosis. With this condition, cholesterol, calcium and other blood components form blockages in your arteries. These blockages, or plaques, can lead to a heart attack or stroke. Several factors can cause short- and long-term fluctuations in your blood cholesterol level. Familiarizing yourself with modifiable factors that may cause fluctuations in your cholesterol may help you reduce your risk of atherosclerosis.
Daily Variation
Your cholesterol level changes throughout the day and is typically lowest when you awake in the morning. After you eat, your blood cholesterol level temporarily increases as your body absorbs fat from the food you have ingested. The more fat in the food you have eaten, the greater the level of increase in your blood cholesterol level. When you have your blood cholesterol level checked, you must abstain from eating or drinking anything but water for nine to 12 hours before the test to ensure that the reading is not influenced by food-related fluctuations.
Dietary Variation
The amount of cholesterol, saturated fat and trans fat in your day-to-day diet is a significant factor influencing your blood cholesterol level. If you eat a diet high in these fats, you have an increased risk of developing an abnormally elevated blood cholesterol level. Conversely, if you have an elevated blood cholesterol level and reduce the amount of animal fats in your diet, your blood cholesterol level may gradually decrease, possibly returning to normal.
Illness and Pregnancy
Your cholesterol level may fall if you develop certain illnesses or conditions. An overactive thyroid gland, for example, can cause a decrease in your blood cholesterol level. Liver disease can also affect your cholesterol level because your liver manufactures a significant portion of your blood cholesterol. A serious infection or accident, major surgery, an arthritis flare-up and other medical conditions that stress your organ systems can cause a short-term decrease in your blood cholesterol level. By contrast, pregnancy causes a temporary increase in your blood cholesterol level. Your cholesterol level returns to baseline level after your baby is born.
Drug-Induced Fluctuations
Prescription and illicit drugs can cause temporary fluctuations in your blood cholesterol level. Common prescription medications that may increase your cholesterol level include oral contraceptive pills; corticosteroids for inflammatory conditions; beta blocking agents used for high blood pressure, heart rhythm abnormalities and heart disease; sulfonamide antibiotics; and thiazide-type water pills. Anabolic steroids, which are often abused for athletic performance enhancement, can also increase your cholesterol level. Medication-related increases in your blood cholesterol level are temporary and typically resolve after discontinuing the drug.
