A good fasting blood sugar level for someone without diabetes is 70 to 99 mg/dL, measured after at least eight hours without eating. After a meal, blood sugar in a healthy person stays below 140 mg/dL within two hours. These numbers shift depending on whether you’re managing diabetes, pregnant, or older with other health conditions.
Normal Blood Sugar at a Glance
Your blood sugar doesn’t stay at one number all day. It rises after you eat and drops between meals, and healthy bodies keep it within a fairly tight range. The key benchmarks for someone without diabetes are:
- Fasting (no food for 8+ hours): 70 to 99 mg/dL
- Two hours after eating: below 140 mg/dL
If your fasting level sits between 100 and 125 mg/dL, that falls into the prediabetes range. A fasting reading of 126 mg/dL or higher on two separate tests meets the diagnostic threshold for diabetes. These cutoffs aren’t arbitrary. They reflect the point at which the risk of complications, particularly damage to blood vessels and nerves, begins to climb meaningfully.
What A1C Tells You That a Single Reading Can’t
A single blood sugar reading is a snapshot. Your A1C, sometimes called hemoglobin A1C, gives you a three-month average by measuring how much sugar has attached to your red blood cells over their lifespan. It’s the most reliable way to see overall blood sugar trends.
- Normal: below 5.7%
- Prediabetes: 5.7% to 6.4%
- Diabetes: 6.5% or higher
A diagnosis of diabetes typically requires two abnormal test results, either from the same blood draw or on separate occasions, unless symptoms like excessive thirst, frequent urination, and unexplained weight loss are already obvious. In that case, a single random blood sugar reading of 200 mg/dL or above is enough to confirm the diagnosis.
Targets If You Have Diabetes
If you’ve been diagnosed with diabetes, “good” blood sugar is defined differently than for someone without it. The American Diabetes Association recommends these goals for most non-pregnant adults with diabetes:
- Before meals: 80 to 130 mg/dL
- One to two hours after starting a meal: below 180 mg/dL
- A1C: below 7.0%
These targets are looser than the normal range for a reason. Pushing blood sugar too low with medication carries its own dangers, including dizziness, confusion, and loss of consciousness. The goal is to find a range that prevents long-term complications without causing dangerous lows. Your doctor may set tighter or more relaxed goals depending on how long you’ve had diabetes, what medications you take, and your overall health.
How Targets Change for Older Adults
Most guidelines recommend that healthy older adults aim for the same A1C target as the general population, around 7.0% to 7.5%. But for older adults living with multiple chronic conditions, cognitive decline, or frailty, the targets relax considerably. Most clinical guidelines suggest an A1C of 8.0% or even up to 8.5% for these individuals.
The reasoning is straightforward. Low blood sugar episodes are especially dangerous for older adults because they increase the risk of falls, confusion, and heart events. The benefits of very tight blood sugar control take years to materialize, and for someone with a shorter life expectancy or significant frailty, the immediate risk of a severe low outweighs those long-term benefits. Medication choices in this age group also prioritize avoiding drugs that can cause blood sugar to crash.
Blood Sugar Targets During Pregnancy
Pregnancy requires tighter blood sugar control because even moderately elevated glucose can affect fetal development. If you’ve been diagnosed with gestational diabetes, the targets are:
- Fasting: 95 mg/dL or below
- One hour after eating: 140 mg/dL or below
- Two hours after eating: 120 mg/dL or below
Women who had type 1 or type 2 diabetes before pregnancy have even stricter goals, with peak post-meal readings ideally between 100 and 129 mg/dL and an A1C below 6.0%. These targets assume they can be reached without frequent episodes of dangerously low blood sugar. If low blood sugar becomes a recurring problem, the goals are adjusted upward.
When Blood Sugar Drops Too Low
Blood sugar below 70 mg/dL is considered low, and it requires immediate action. Symptoms include shakiness, sweating, a fast heartbeat, irritability, and feeling suddenly hungry. As levels drop further, you may experience confusion, blurred vision, or difficulty speaking.
The standard treatment is the “rule of 15”: consume 15 grams of fast-acting carbohydrate (four glucose tablets, four ounces of juice, or a tablespoon of honey), wait 15 minutes, and recheck. Most low blood sugar episodes happen in people taking insulin or certain oral diabetes medications, not in people without diabetes. If you don’t take these medications and regularly feel symptoms of low blood sugar, that’s worth investigating with your doctor for other causes.
When and How to Check
If you don’t have diabetes, you likely don’t need to test at home. A fasting blood sugar or A1C drawn at your annual physical gives a reliable picture. But if you’re managing diabetes with insulin or other medications, the timing of your checks matters.
For people on multiple daily insulin injections, the most useful times to test are before meals and snacks, before bed, and before and after exercise. If you use a long-acting insulin once or twice a day, testing before breakfast and occasionally before dinner or at bedtime is often enough. The goal is to catch patterns: Are you consistently high in the morning? Do certain meals spike you more than others? Those patterns guide adjustments to food, activity, and medication far more effectively than a single isolated number.
Continuous glucose monitors, which read your levels automatically every few minutes, have made this easier for many people. They reveal trends that fingerstick testing can miss, like blood sugar spikes in the middle of the night or gradual rises after specific foods.