Complications of Type 1 Diabetes
- Blindness (retinopathy)
- Kidney disease (nephropathy)
- Heart disease
- Nerve disease (neuropathy)
HypoglycemiaHypoglycemia is low blood sugar, usually 50-60 milligrams per deciliter (mg/dL) or 2.8-3.3 millimoles per liter (mmol/L). It can be caused by any of the following:
- Taking too much insulin for the amount of food you ate
- Taking too much insulin to treat "fasting" blood sugar
- Skipping a meal or eating a smaller meal than usual without lowering your insulin dose
- Exercising harder or longer than normal without lowering your insulin dose
- Rapid heart rate
- Pale skin color
- Sudden moodiness or behavior change, such as crying for no apparent reason
- Clumsy or jerky movements
- Confusion or difficulty paying attention
- Tingling sensations around the mouth
- Passing out leading to coma
- 1-2 glucose tablets or the equivalent of glucose gel
- 4 ounces of fruit juice or cola (15 grams of carbohydrates)—In general, 15 grams of carbohydrates should raise blood sugar 25-50 mg/dL (1.4-2.8.mmol/L)
- 3 graham crackers (15 grams of carbohydrates)
- 5-6 pieces of hard candy
HyperglycemiaHyperglycemia is high blood sugar. Long-term hyperglycemia is the major cause of many of the long-term complications that occur in people with diabetes (discussed below) though short-term hyperglycemia can cause a life-threatening condition caused diabetic ketoacidosis. Hyperglycemia occurs when you do not have enough insulin to dispose of the glucose in your body. It can be caused by any of the following:
- Taking too little insulin for the food that you ate
- Eating without taking any insulin
- Eating a larger meal than usual without adjusting the insulin dose
- Exercising more or less than you planned without adjusting the insulin dose
- Being stressed from an illness or life events (may require adjusting the insulin dose)
- High levels of sugar in your urine—ask your doctor if you should be monitoring your urine
- Frequent urination (polyuria)
- Increased thirst (polydipsia)
- Blurred vision
KetoacidosisPeople with type 1 diabetes can develop ketoacidosis, a serious condition that rarely happens in people with type 2 diabetes . When your body is not getting enough insulin, sugar cannot get into the cells to generate energy. When this happens, the body starts breaking down stored fat for energy. The by-products of fat breakdown are ketone bodies, which are acids that build up in the blood that can cause ketoacidosis. The most common reasons for your body to generate ketones are generally the same for hyperglycemia with the following additions:
- Taking too little insulin when you are sick with an infection, the body may need more insulin. This is the setting in which ketoacidosis typically occurs.
- High levels of ketones in the urine or blood
- Fruity smell to the breath
- Abdominal pain
- Nausea and vomiting
- Dry mouth or signs of dehydration
- Reduced mental function and alertness
- Shortness of breath
BlindnessChronic high blood sugar, as well as high blood pressure, can damage tiny blood vessels in the retina of the eye. Diabetes is the most common cause of blindness in individuals between the ages of 20-60 in the United States. This damage, called diabetic retinopathy, usually occurs over a long period of time. Signs of eye damage include:
- Blurry or double vision
- Rings, flashing lights, or blank spots
- Dark or floating spots
- Pain or pressure in one or both of your eyes
- Trouble seeing things out of the corners of your eyes
Kidney DiseaseHigh blood sugar and high blood pressure damage the kidneys’ glomeruli, which are responsible for filtering waste out of the blood. This damage allows protein to leak out of the glomeruli and causes wastes that otherwise would be excreted with the urine to build up in your blood. Having small amounts of protein in the urine is called microalbuminuria. Your doctor will order a urine test yearly to monitor for this. Two classes of drugs, angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers, can reduce the leakage of protein in the urine and delay the onset of diabetic kidney disease.As damage continues, more protein is leaked and more wastes build up. Having larger amounts of protein in the urine is called proteinuria or macroalbuminuria. Eventually, this damage can progress to kidney failure, which requires dialysis or a kidney transplant.Restricting protein intake in diabetic patients with chronic renal failure can lower the death rates.
Heart DiseasePeople with type 1 diabetes are more likely to have heart disease and to die from heart disease as people without diabetes. Having diabetes can cause your blood cholesterol levels to rise, leading to clogged, narrowed arteries, a condition called atherosclerosis . Clogged arteries make it more difficult for blood to carry oxygen and other essential nutrients to vital organs and tissues, such as your heart, and can cause:
- Chest pain (also called angina )—This pain or pressure feeling usually starts in your chest and radiates to your arm and may worsen when you exercise or after a full meal. People with long-term diabetes may not have chest pain. They need to be aware of other signs like sudden weakness or shortness of breath.
- Heart attack —This is caused by the blockage of a blood vessel that supplies oxygen and other essential nutrients to your heart. When part of your heart muscle doesn't receive the nutrients it needs to function, it stops working. Symptoms include chest pain or pressure feeling, nausea, indigestion, extreme weakness, and sweating. Symptoms may be blunted in people with chronic diabetes.
- Cardiomyopathy —This is a weakening of the heart muscle caused by the narrowing of small blood vessels throughout the heart.
StrokeType 1 diabetes makes you 2-4 times more likely to have a stroke . A stroke is caused by a blockage of blood flow to the brain. The effects of a stroke depend on the part of your brain that is damaged and may include:
- Sudden weakness or numbness of your face, arm, or leg on one side of your body
- Sudden confusion, trouble talking, or trouble understanding
- Sudden dizziness, loss of balance, or trouble walking
- Sudden trouble seeing in one or both eyes or sudden double vision
- Sudden severe headache
Nerve DiseaseMany people with diabetes have mild-to-severe forms of diabetic nerve damage, called diabetic neuropathy . Having high blood sugar for many years can damage the blood vessels that bring oxygen to nerves. High blood sugar can also hurt the covering on the nerves. Damaged nerves may stop sending messages, or, they may send messages too slowly or at the wrong times. Nerve damage due to diabetes could manifest as:
- Numbness, tingling, or burning of the hands and feet
- Erectile dysfunction
- Foot ulcers resulting from loss of sensation
- A drop in blood pressure upon standing up
- Diarrhea at night
- Difficulty swallowing
- Neurogenic bladder with dribbling, weak stream, or hesitancy
- Sweating after meals
Reduce Your Risk of ComplicationsHave Regular CheckupsYour doctors can often spot early signs of complications. Perhaps more importantly, most of the complications listed above can be prevented be following recommended standards for diabetic care.If you have had diabetes for several years, your doctor may recommend that you:
- Have frequent (every 3-6 months) measurements of glycosylated hemoglobin (Hba1c) to ensure effective treatment.
- Have yearly eye exam using drops to dilate the pupils.
- Have periodic foot exam with a nylon monofilament to determine that sensation is normal.
- Have yearly urine test to detect microalbuminuria.
- Have careful control of blood pressure, low-density lipoproteins (LDLs), and triglycerides to reduce long-term risk of heart disease and stroke. Talk with your doctor about the right ranges for you.
- Have yearly flu and periodic pneumococcal vaccines to reduce the risk of pneumonia .
- Take low-dose aspirin every day, depending on your age and risk factors.
- Blood sugar levels
- Blood pressure levels
- Vision problems, such as blurriness or spots
- Pale skin color
- Numbness or tingling feelings in hands or feet
- Repeated infections or slow healing of wounds
- Chest pain
- Vaginal itching
- Constant headaches
- Cuts or blisters on your feet
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2/7/2008 DynaMed's Systematic Literature Surveillance https://dynamed.ebscohost.com/about/about-us: Armstrong DG, Holtz-Neiderer K, et al. Skin temperature monitoring reduces the risk for diabetic foot ulceration in high-risk patients. Am J Med. 2007;120:1042-1046.
2/7/2008 DynaMed's Systematic Literature Surveillance https://dynamed.ebscohost.com/about/about-us: Lavery LA, Higgins KR, et al. Home monitoring of foot skin temperatures to prevent ulceration. Diabetes Care. 2004;27:2642-2647.
- Reviewer: Kim A. Carmichael, MD, FACP
- Review Date: 09/2014
- Update Date: 09/17/2014