Most people have slightly higher blood sugar levels in the morning. This is often nothing to worry about, but if the levels are consistently high, this could indicate diabetes.
Diabetes is a condition that impairs the body’s ability to process blood glucose. Without management, blood sugar levels can become too high. Even when a person carefully controls the condition, they may notice blood sugar spikes when they wake up.
There are three potential mechanisms behind this, including:
- the dawn phenomenon
- waning insulin levels
- the Somogyi effect, though some experts dispute this
This article explores the potential causes of high blood sugar in the mornings, including what it can mean for a person’s health and when to see a doctor.
The dawn phenomenon refers to periods of hyperglycemia, or high blood sugar, that
Hormones, such as cortisol, glucagon, epinephrine, and growth hormone, are known as counter-regulatory hormones. They can cause blood sugar levels to rise. The activity of cortisol and growth hormone usually increases each day to stimulate the liver to produce glucose at dawn.
This is why everyone experiences a slight rise in their blood glucose levels to some extent in the morning. A person without diabetes will not experience adverse effects, as their body can quickly produce insulin to bring levels back down.
However, a person with diabetes is unable to produce sufficient or effective insulin. As such, this can cause a blood sugar spike and may require treatment.
When the dawn phenomenon occurs, it may coincide with when nighttime insulin levels begin to taper off. Reasons for the drop in insulin can vary. However, it often occurs when a person administers too little basal insulin or injects it too early, causing its effects to wear off earlier than desired.
This theory, named after Dr. Michael Somogyi, suggests that blood sugar levels rise in response to an episode of late night hypoglycemia or low blood sugar. This could occur if a person administers too much insulin or does not eat enough food before bed.
However, some research has disproven the Somogyi effect. The scientific community still debates the theory.
Temporarily elevated blood sugar in the morning has various other causes. Possible factors include:
- dehydration
- stress
- infections, such as viral illnesses
- acute or long-term pain
- menstruation
- certain medications
The
However, it is important to note that in those without diabetes, the body will release more insulin to adapt to this, resulting in blood sugar levels returning to usual.
If blood sugar levels continue to be significantly high in the mornings, a person should contact a doctor.
People can test their blood sugar levels using at-home devices to check their blood sugar levels at bedtime, in the middle of the night, and upon waking to understand their glucose patterns better. This may also help a doctor identify the cause of spikes in the morning.
People with diabetes may wear a continuous glucose monitor (CGM) to help them track and monitor their blood glucose throughout the night and day. This wearable medical device can collect data on a person’s blood sugar levels while they sleep.
People who do not already have a diagnosis or do not have a blood glucose monitor might consider speaking with a doctor about testing. The doctor may recommend a urine test first thing in the morning to determine if a person may have diabetes.
Treatment options for high morning blood sugar will vary depending on the cause. By tracking when the highs and lows occur, a doctor will be able to recommend suitable strategies.
For example, if the test results show that a person has high blood sugar at bedtime and in the morning, then food or insufficient diabetes medication could be responsible. A person can adjust this by changing what and when they eat, slightly increasing their insulin dosage or both.
If a person with diabetes is within their target range at bedtime but wakes with high blood sugar, they may be using too little basal medication or injecting it too early. Changing the timing of the long-acting dose, switching to a twice-daily basal insulin, or using an ultra-long-acting basal insulin may be beneficial.
Data demonstrating that a person has high blood sugar between roughly 3 a.m. and 8 a.m. suggests the dawn phenomenon. In this situation, a doctor may recommend that a person does not increase their long-acting insulin, as this could cause hypoglycemia during the night.
A healthcare professional might recommend a person uses an insulin pump that they can program to deliver more insulin in the early morning hours automatically.
Some research
- exercising in the evening
- increasing the protein-to-carbohydrate ratio in the evening meal
- eating breakfast every day
Regularly experiencing high morning glucose levels could increase the risk of:
- insulin resistance
- cardiovascular disease
- more rapid disease progression for those with diabetes
Anyone who experiences high blood sugar levels in the morning should speak with a doctor who can identify an effective way to manage it.
Slightly elevated morning blood sugar levels are fairly typical but typically return to usual levels in most people. If they do not, a person may need to contact a doctor for advice.
Potential causes include the dawn phenomenon and waning insulin levels. However, other factors, such as a lack of sleep, caffeine, stress, and other illnesses or medications can also influence blood sugar levels.
People with diabetes can monitor their blood glucose levels at different times of the day. This information can help a doctor recommend other ways of managing high blood sugar levels in the morning.
People who do not currently have a diabetes diagnosis and who notice consistently high blood sugar in the morning should contact a doctor.
