When blood sugars are high, known as hyperglycemia, or low, known as hypoglycemia, people can experience a variety of symptoms that range from mild to serious. People with untreated symptoms can develop serious or life threatening complications.
After consuming food containing carbohydrates, the digestive system can break it down into a type of sugar called glucose, the body’s primary source of energy.
This sugar then enters the bloodstream, and the hormone insulin allows glucose to enter cells and provide them with the energy to function.
Insulin plays a vital role in regulating blood sugar. If the body is unable to produce sufficient insulin or the cells do not respond to insulin, it may have difficulty managing blood sugar levels. This can result in a person experiencing or hyperglycemia or hypoglycemia.
This article discusses the symptoms and potential complications of hyperglycemia and hypoglycemia.
- polydipsia, or feeling very thirsty
- having a very dry mouth
- feeling very tired
- blurred vision
- weight loss
- polyuria, or often needing to urinate
glucosuria , or having high levels of glucose in a person’s urine
If a person has
- have an altered
mental state , such as changed mood or problems with their cognitive processes - have focal neurologic problems, or issues with their nerves, brain, or spinal cord in a specific body area
- go into a coma
If a person has untreated or uncontrolled hyperglycemia for a long time, they may
- Retinopathy: This refers to damage to the blood vessels at the back of a person’s eye. People with
retinopathy may lose their vision or become blind. - Nephropathy: This describes the deterioration of a person’s kidney function. People with nephropathy may eventually have
kidney failure . - Neuropathy: This is damage to a person’s nervous system. People with
neuropathy may feel weakness, numbness, and pain in their hands and feet. - Coronary artery disease (CAD): This is the most
common form of heart disease in the United States. People with CAD can have chest pains, heart attacks, or heart failure. - Cerebrovascular disease: This condition
restricts the blood flow to a person’s brain. This can lead to brain damage or strokes. - Peripheral vascular disease (PVD): People with
PVD have decreased blood flow to their arms, legs, and some internal organs. PVD can eventually cause a person’s tissue to die, sometimes leading to limb amputation. People with PVD can also have heart attacks or strokes.
People with hypoglycemia have symptoms that develop quickly. Symptoms can vary from person to person. Mild or moderate symptoms
- hunger
- being tired
- feeling shaky
- feeling dizzy or lightheaded
- feeling confused or irritable
- fast or unsteady heartbeat
- headaches
- not being able to see clearly
- not being able to speak clearly
If a person has severe hypoglycemia, their blood glucose levels get very low. Symptoms of severe hypoglycemia may include:
Severe hypoglycemia can be a life threatening medical emergency that requires urgent medical attention.
People with mild or moderate low blood sugar can treat their symptoms quickly by consuming sources of fast-acting glucose, such as candy, fruit juice, or soda. However, severely low blood sugar can quickly
- passing out
- seizures
- brain damage
- coma
In some cases, these complications can be fatal.
The body
Triggers that may
- eating large amounts of food, particularly carbohydrate-rich foods
- not being physically active
- not having enough insulin due to medical conditions, such as diabetes or not taking enough diabetes medication
- side effects from certain medications, such as steroids or antipsychotic medication
- illness
- stress
- sunburn
- menstruation
- lack of sleep
- short- or long-term pain
- dehydration
- coffee
- gum disease
Learn about blood sugar spikes with diabetes.
Triggers that can lower a person’s blood sugar levels include:
- missing meals or not eating enough food
- eating food with fewer carbohydrates than usual
- drinking alcohol, especially if a person has an empty stomach
- too much insulin due to taking too much diabetes medication
- doing more physical activity than usual
- being in extreme heat
People’s blood sugar levels also rise and fall naturally over the course of a day.
People can
- exercising regularly
- eating a healthy diet that includes plenty of fruit and vegetables
- taking any medication as their doctor prescribes
- eating at regular times
- avoiding skipping meals
- eating foods low in trans or saturated fats
- eating foods low in sugar and salt
- drinking water instead of juice or soda
- limiting their alcohol intake
Learn about 12 foods that will not increase blood sugar levels.
People’s bodies normally regulate their blood sugar levels as they eat and absorb food. If a person’s body cannot regulate their blood sugar level, they may experience various symptoms of hyperglycemia or hypoglycemia. These symptoms can be mild, moderate, or severe. People with severe symptoms may require urgent medical attention.
People with constantly high or low blood sugar can develop complications over time without treatment. These complications can be serious or fatal. However, people can take simple steps to help manage and regulate their blood sugar levels and avoid complications.
Learn more about blood sugar levels and diabetes in our dedicated hub.