Chills without fever can be caused by a number of conditions.
1. Exposure to cold
You may experience chills because you are in a very cold place, such as the ocean or a pool, or outside on a chilly day. You can also get chills if your clothing becomes damp or wet. You can get chills indoors, too, if the air-conditioning is set too cold or the heat isn’t hot enough.
2. Medication side effect
Chills without fever may result from taking certain medications or combinations of medications. They may also occur if you take the incorrect dosage of an over-the-counter medication, herbal supplement, or prescription drug.
3. Reaction to extreme physical activity
Marathon running or other forms of extreme sports that require intense physical exertion may cause changes to your core body temperature. That can result in chills.
4. Hypothyroidism (underactive thyroid)
An underactive thyroid is a thyroid gland that doesn’t produce enough of the hormones needed to regulate metabolic rate or support overall health. This condition can cause an increased sensitivity to cold, resulting in chills.
Hypoglycemia occurs if blood sugar levels dip abnormally low. If you have diabetes, it may be a sign that your medication or diet needs to be adjusted. It’s also possible to experience hypoglycemia without diabetes.
Malnutrition occurs when your body lacks necessary nutrients. This can happen because of poor access to nutritious foods, an underlying condition that affects your body’s ability to properly absorb nutrients, or an eating disorder, like anorexia. Without the correct balance of nutrients, your body can’t properly function.
7. Emotional reaction
Chills can occur if you have a profound or intense emotional reaction to a situation. Emotions that might cause chills include fear or anxiety.