Symptoms of Hypoglycemia

One of the common minor complications of diabetes is hypoglycemia. It is a condition that affects the individual physically. If it recurs, it may also have an emotional impact upon the diabetic’s family, friends and partners, as well as the person’s own stress and anxiety levels.[1] It is important to be aware of the symptoms. It is best, however, to understand what hypoglycemia is first.

Defining Hypoglycemia

The simplest way to describe hypoglycemia or “hypoglycemic disorder” is that it is low blood glucose.[2] Glucose is the source of energy that both your body and brain and body require to operate efficiently. If you want to keep healthy, you have to maintain the levels of glucose in your body at a specific “normal” level. These levels must neither be too high nor too low, though they can fluctuate between norms. There are also differences for fasting blood glucose levels and levels after meals.

In general, normal blood sugar levels are above 70 mg/dL. Hypoglycemia can start to cause symptoms below 70 mg/dL, but will almost always causes symptoms if your blood sugar falls below 55 mg/dL. This is true whether you are diabetic, prediabetic or do not have diabetes at all.[4] The symptoms do vary, but not significantly by type of diabetes but rather accordance to age and stage – specifically how low your glucose levels have fallen. Moreover, the symptoms will not manifest themselves uniformly and not all individuals will suffer the exact same symptoms in the same order or fashion.

The Symptoms of Hypoglycemia

There are several ways to classify the symptoms of hypoglycemia. The usual symptoms are divided into adrenergic or neuroglycopenic. The former indicates the rapid fall of blood glucose levels; the latter reveals symptoms realized from not having enough glucose present to meet the needs of the brain. In a similar but more direct fashion, some divide the symptoms into two separate but related types: those that affect the physical body and those that affect the central nervous system (CNS).

Those who affect the body or physical component include:

  • Rapid heart beat
  • Tremors or shaking
  • Sweating or noticeable perspiration
  • Nausea
  • Hunger – a very urgent desire to eat

Those reflecting the impact on the CNS include the following[5]:

  • Light headedness or slight dizziness
  • Confusion
  • Headache
  • Feeling weak
  • Anxiety
  • Slurred speech
  • Difficulty in talking or communicating
  • Delayed reflex actions
  • Seizures or convulsions
  • Sleepiness
  • Unconsciousness or coma

It is argued that hypoglycemia alters the mood. If the problem recurs, it can also lead to elevated levels of anxiety. These, in turn, affect how an individual manages life due to less energy and self-efficacy. The overall effect can result in lower self esteem, greater fear of another episode and decreased cognitive performance.[6]

Who is at Higher Risk?

If you wish to understand how to prevent hypoglycemia, you first need to understand who is at greatest risk. If you are a diabetic, whether type 1 diabetes (T1D) or type 2 diabetes (T2D), you increase your risk of an incident if you do any of the following:

  • Miss your snack
  • Eat different food than you normally do without knowing the amount of carbohydrates the items contain
  • Eat less than you need to after an insulin injection
  • Consume alcohol, particularly on an empty stomach
  • Participate in physical activity without taking the right precautions. Physical activity requires energy and therefore the more glucose you burn, the more your glucose levels will fall. You need to adjust your insulin levels to meet these requirements
  • Take part in long lasting physical activities – these will require very careful planning of your insulin dosage
  • Stress
  • Heat

All these can influence your glucose levels. They put you at risk of becoming hypoglycemic.


Knowing the risks is a good start. It helps you recognize the need to be proactive in taking care of your diabetes. Yet, being proactive means understanding as much as you can about the levels of blood glucose. It means you need to educate yourself and become diabetes-literate.

Being diabetes literate means you know the pattern of your blood glucose and how it relates to your current form of medication. If you are T1D, you must understand the peak action of your insulin. You need to be able to time it so you can balance it at the right time, perhaps with a carbohydrate snack or food. If you take pills, you need to understand how the various medications interact to create a normal blood glucose level.

Prevention of complications is all about knowing your body. It means you have to understand what is happening and how to “fix” it. In this case, you need to make sure the blood glucose levels are within the proper boundaries no matter what you are planning in order to prevent hyperglycemia. To manage the symptoms, you need to ensure the conditions are not right for them to develop, that the risks are downgraded and that you are prepared should they appear.

Behavioral change is generally necessary to combat hypoglycemia. Awareness of the potential causes as well as possible consequences is essential. Behavioral modification is possible.[7] It is a means of approaching the disorder and challenging yourself to not be fearful or anxious about possible hypoglycemia episodes in the future by preventing them in the first place.

This does not mean hypoglycemia will not occur. It does so with regularity among T1D as they learn how to manage their diabetes. When it does, however, the trick is to identify what caused it. Was it the injection or insulin-stimulating pill taken in the morning or later? Find out what was responsible and then adjust accordingly.


Hypoglycemia occurs in all diabetics at some point. There are causal factors and sometimes some seemingly innocent activity can trigger the episode. You need to identify what typically tends to cause hypoglycemia in your life and take steps to prevent it from occurring. This is a strategy that can be used to deal with many of the complications of diabetes.


[1] Donnelly, LA; Morris, AD; Frier, BM; Ellis, JD; Donnan, PT; Durrant, R; Band, MM; Reekie, G; Leese, GP; and the DARTS/MEMO Collaboration (2005). “Frequency and Predictors of Hypoglycaemia In Type 1 and Insulin-Treated Type 2 Diabetes: A Population Based Study. Diabetic Med, 22(6):749–755.

[2] Marcovitch, H (2006). Black’s Medical Dictionary 41st edition. Lantham, Maryland: Scarecrow Press.

[3] Levin, ME; and Pfeiffer, MA (editors) (2009). The Uncomplicated Guide to Diabetes Complications, 3rd ed. Alexandria, VA: ADA.

[4] Flegg, A (2006). Hypoglycemia: The Other Sugar Disease. Ottawa, ON: Book Coach Press.

[5] Bhasin, S;  Cryer, PE; and  Vigersky, R (2009). “Patient Guide on the Diagnosis and Management of Hypoglycemic Disorders (Low Blood Sugar) in Adults.” The Journal of Clinical Endocrinology & Metabolism, 94(3): 0.

[6] Perlmuter, LC; Flanagan, BP; Shah, PH; and Singh, SP (2008). “Glycemic Control and Hypoglycemia: Is the Loser the Winner?” Diabetes Care, 31: 2072– 2076.

This article was originally published July 12, 2012 and last revision and update of it was 9/10/2015.