When to Check Your Blood Sugar
Studies show that people with diabetes who maintain normal or near-normal blood glucose (sugar) levels are at a reduced risk for complications. If you have diabetes, it is best to keep your blood sugar in a target range to reduce the risk of problems, including diabetic kidney disease (nephropathy), eye disease (retinopathy), nerve disease (neuropathy), heart attack, or stroke. Some individuals can work toward lower numbers, while some may need higher goals. You need to work closely with your doctor to set your personalized target range for your blood sugar. This target will help you achieve control of your blood sugar without having a high risk of dangerous spikes or drops.
But, just how often does one need to check blood sugar levels? The answer to this question depends on important information about your specific condition. Specifically, here are the factors you may need to consider to know when to check your blood sugar:
- The type of diabetes you have (e.g., type 1, type 2, gestational diabetes)
- Your treatment or management (i.e., lifestyle, use of insulin or oral medications)
This article will discuss the following topics:
- When to check blood sugar for type 1 diabetes
- When to check blood sugar for type 2 diabetes
- When are the best times in a day to check blood sugar?
- When to check blood sugar more frequently
- When to contact the doctor
- When to test blood sugar: The different types of tests• Factors that affect blood sugar values
If you have type 1 diabetes, your healthcare provider may have advised you that frequent testing is the only safe way to manage your blood sugar levels effectively. You may need to test at least four times daily.
If you are using an insulin pump (e.g., continuous subcutaneous insulin infusion), or if you give yourself three or more insulin injections daily, you may need to test as many as ten times daily or more.
• For individuals with type 2 diabetes, the frequency of testing may depend on factors, including your treatment (lifestyle, insulin, oral medications), risk for extreme blood sugar levels (especially low blood sugar), and goals of management.
- As advised, most people with diabetes check their blood sugar first thing when they wake up before eating (called “fasting” blood sugar), and also before taking other meals in a day. Here’s a list of the best times in a day to check your blood sugar:
- Before breakfast (with fasting)• Before lunch• Before dinner• Two (2) hours after starting a meal (called “postprandial”)
- Before bedtime
- Before driving
- Before, during, and after performing rigorous exercise
- When you have symptoms of high or low blood sugar
- When you are feeling sick or stressed
- When you are having less or more physical activity than usual
- When you are experiencing changes in eating habits or daily routines (e.g., when traveling)
- When adjusting/changing insulin or medication
- When you are having symptoms of low blood sugar (e.g., sweating, blurred vision, shakiness, a fast heartbeat)
- When you are having symptoms of high blood sugar (e.g., increased thirst, frequent urge to urinate, nausea, vomiting, headaches, fatigue)
- When you experience morning headaches or night sweats
- When the trend of your blood sugar readings are above the target range
- When you are pregnant
- When you’re recovering from or preparing for surgery
- When you are starting on new medications that can affect blood sugar (e.g., steroids)
Seek medical attention immediately when your blood sugar readings are in the extreme range (i.e., either a fasting blood sugar greater than 360mg/dL or less than 70mg/dL), especially with two or more abnormal readings.
Recognizing the “red flags” of high and low blood sugar iscrucial to your health condition. Thus, it is essential for you to be wary of the signs and symptoms of hyperglycemia (high blood sugar) and hypoglycemia (low blood sugar).
When your blood sugar has dropped below the normal range (typically less than 70mg/dl), you may feel:
- lightheaded or with headaches
- hungry, weak, or drowsy
- irritable, nervous, or anxious
- confused and unable to concentrate
- tingling or numbness on your lips or tongue
- an increased heartbeat
With a very low blood sugar (less than 50mg/dl), you may experience severe symptoms such as:
- a seizure loss of consciousness
What to do when your blood sugar gets too low
A condition of low blood sugar level can be dangerous and needs to be treated without delay. If you are taking oral medications or insulin, you may have a greater chance of having low blood sugar. If you feel very hungry, sweaty, and shaky, you need to check your blood sugar right away.
Even if you do not feel any of these symptoms but think you may have low blood sugar, check your blood sugar at once. If your meter reading confirms a blood sugar lower than 70 mg/dL, do one of the following immediately:
- Drink four (4) oz. of fruit juice
- Drink four (4) oz. of regular soda
- Chew four (4) hard candies
- Chew four (4) glucose tablets
After taking one of these, recheck your blood sugar after 15 minutes. Repeat eating any one of the mentioned until your blood sugar is above 70 mg/dL. After your blood sugar has reached over 70 mg/dL, you should grab a snack if the next meal is one hour or more away.
When you have high blood sugar (typically above 180mg/dl), signs and symptoms may include:
- have the urge to urinate frequently, especially at night
What to do when your blood sugar gets too high
Having blood sugar that’s beyond your target levels (typically over 180 mg/dL) over time can lead to serious health complications. After having a high reading accompanied by feelings of tiredness, thirst, frequent urge to urinate, or blurry vision, you may have a blood sugar spike. One way to lower this is to drink lots of water and have a brisk walk or exercise. Contact your healthcare provider if this becomes a trend for more than three times in two weeks, and you have no clue why.
1. Fasting Blood Sugar (FBS) – this measures blood sugar after you have not taken any meals for at least eight (8) hours. FBS is the first test often requested by your healthcare provider to determine whether you have pre-diabetes or diabetes.
2. Two (2)-hour postprandial blood sugar – this measures blood sugar exactly two hours after you have started eating a meal. This test is not used to diagnose diabetes.
3. Random blood sugar (RBS) – this measures blood sugar regardless of when you last ate a meal. Several random measurements may be checked throughout the day. RBS is useful because sugar levels in healthy people do not change widely throughout the day. Whereas, blood sugar levels that fluctuate widely may indicate a problem.
4. Hemoglobin A1c (also called glycohemoglobin A1c orglycated hemoglobin) – this measures the sugar stuck to your red blood cells, and is also used to diagnose diabetes. If you already have diabetes, this test may be ordered by your doctor to know how well your condition has been controlled in the last two to three months. This is also called your estimated average glucose or eAG.
5. Oral Glucose Tolerance Test (OGTT) – this is used to diagnose pre-diabetes and diabetes. This refers to a series of blood sugar measurements taken after you drink a sweet glucose liquid. OGTT is commonly requested by the doctor to diagnose gestational diabetes (diabetes during pregnancy)
Several factors can influence how your blood sugar levels spike or drop. Knowing these factors can help you prevent wide swings in your blood sugar values.
What makes my blood sugar rise?
- a snack or meal
- sedentary lifestyle or inactivity
- insufficient diabetes medication
- side effects of other drugs
- illness or infection
- hormonal changes (e.g., during menstrual periods)
What makes my blood sugar fall?
- a snack or meal with less food (fewer carbohydrates) than usual
- skipping a snack or meal
- rigorous physical activity
- too much diabetes medication
- side effects of other drugs
- drinking alcoholic drinks, especially with an empty stomach
With diabetes, knowing when to take your blood sugar is vital. However, it’s normal to feel frustrated or even guilty when you see that your blood sugar is beyond the targeted range. Try to think of your meter readings as helpful information that can help you and your healthcare provider manage your condition better. Whether too high or too low, you can use the results of your blood sugar to your advantage in making decisions about medication, food, and physical activity. These informed decisions should help you feel your best daily and prevent or delay unwanted diabetes complications.