Why Am I Always Cold? 9 Reasons Why You Can't Stop Shivering

Constantly feeling cold is not only uncomfortable, but it could be a sign of an underlying health problem like hypothyroidism, a vitamin deficiency, or simply not getting enough sleep.

It's normal to feel cold in colder climates, but if you notice that you're constantly feeling cold, even when you're not in colder temperatures, there may be an underlying cause. Here are nine possible reasons why you're always feeling cold.

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1. Low Body Weight

Low body weight—which the Centers for Disease Control and Prevention (CDC) defines as having a BMI below 18.5 kg/m²—can keep you feeling cold for a couple of reasons.

First, when you're underweight, you lack an adequate level of body fat to insulate you from cold temperatures, Maggie Moon, RD, a Los Angeles–based nutritionist, told Health.

Plus, a low BMI may mean that you have less fatty tissue, which, according to a 2022 study published in the EPMA Journal, can cause your body to produce less heat.

How to treat it: If you're underweight, talk to your healthcare provider, who will run tests to see what's causing your low body weight. They may also suggest you put on a few pounds by loading up on whole, healthy foods that contain protein, fat, and complex carbohydrates.

2. Hypothyroidism

"Always being cold is a telltale sign of hypothyroidism, which means your thyroid doesn't secrete enough thyroid hormone," Holly Phillips, MD, an internist at Lenox Hill Hospital in New York City, told Health. Without the right level of this hormone, your metabolism slows, preventing you from generating adequate heat.

The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) states that nearly 5% of Americans have this condition. Rates are higher in cisgender women and those who are over age 50, according to MedlinePlus. MedlinePlus notes that signs of hypothyroidism include:

How to treat it: If you suspect a thyroid problem, see your healthcare provider, who can confirm the diagnosis with a blood test and treat the condition appropriately.

3. Iron-Deficiency Anemia

Low iron levels are one of the most common reasons for chronic coldness. That's because iron helps red blood cells carry oxygen throughout your body, so it's able to produce heat, Dr. Phillips explained. Iron is also crucial because a deficiency can slow thyroid functioning, leading to hypothyroidism—which can further leave you feeling cold, Moon said.

According to the National Heart, Lung, and Blood Institute, other symptoms of low iron levels include:

  • Pale skin
  • Brittle nails
  • Difficulty concentrating
  • Shortness of breath

How to treat it: First, you'll want to get a proper diagnosis via a blood test. Then, depending on the severity of your anemia, your healthcare provider may suggest you take iron supplements, get an IV infusion, or boost your intake of iron-rich foods like red meat, leafy greens, and eggs, said Moon.

4. Poor Circulation

If your hands and feet feel cold, but other parts of your body feel warm, a circulation problem that keeps blood from reaching your extremities may be the reason.

One common cause of circulation problems is Raynaud's disease, sometimes called Raynaud's phenomenon. Primary Raynaud's disease, which doesn't develop due to another disease like secondary Raynaud's disease, affects about 10% of the population, according to the American College of Rheumatology.

This condition causes the blood vessels in your hands and feet to temporarily narrow when they sense cold, Margarita Rohr, MD, an internist at NYU Langone Medical Center in New York City, told Health.

Other reasons blood may have a hard time reaching your limbs include cardiovascular disease, which causes your heart to not pump as effectively, or smoking, which constricts blood vessels, Dr. Rohr said.

How to treat it: Take a visit to your healthcare provider, who can determine if the cause of your circulation problems is due to Raynaud's disease. They can direct you towards a treatment plan and also ensure it's not something more serious like cardiovascular disease.

5. Dehydration

If you just can't warm up, it could be a sign that you need to drink more water. "Up to 60% of the adult human body is water, and water helps regulate body temperature," said Moon.

"If you're adequately hydrated, water will trap heat and release it slowly, keeping your body temperature in a comfortable zone. With less water, your body is more sensitive to extreme temperatures," Moon added.

Beyond feeling chilly, Cedars-Sinai notes that other symptoms of dehydration include:

  • Dizziness
  • Lightheadedness
  • Confusion
  • Muscle cramps
  • Tiredness
  • Dark-colored urine
  • Dry Mouth

How to treat it: Aim for eight glasses a day at a minimum, recommended Moon, but always drink more if you're working out or spending time in the sun.

6. Vitamin B12 Deficiency

Not consuming enough vitamin B12—about 2.4. micrograms daily for the average adult—can cause anemia, resulting in chronic coldness, Moon said. According to Johns Hopkins Medicine, symptoms of B12 deficiency include:

  • Numbness or tingling in the hands, legs, or feet
  • Trouble walking
  • Fatigue
  • Nausea
  • Diarrhea

How to treat it: While B12 deficiency is rare in the general population, it's common among vegans or vegetarians since the nutrient is almost exclusively found in animal products, Moon said. Therefore, try taking a supplement if you're plant-based. Otherwise, check in with your healthcare provider, as it may be a sign of an absorption issue.

7. Diabetes

Diabetes that's not kept in check can lead to a condition called peripheral neuropathy, which damages the nerves in your hands and feet, according to the American Diabetes Association.

"When this develops, you experience numbness and sometimes pain in the hands and feet, and since these nerves are also responsible for sending messages to the brain regarding temperature sensation, your hands and feet may feel cold," Dr. Rohr said.

How to treat it: Diabetic nephropathy develops gradually, so you may not realize you have it. But if you have diabetes or have symptoms of the disease, like frequent urination, fatigue, and feeling parched, see your healthcare provider.

8. Minimal Muscle Mass

If you've already paid a visit to your healthcare provider for your constant chills and they've determined you don't have an underlying condition, you may be cold due to a lack of muscle mass.

Muscle helps maintain body temperature by producing heat, said Dr. Rohr, so not having enough muscle tone may contribute to feeling cold.

How to treat it: Hitting the weight room at the gym or investing in free weights can help build muscle.

9. Lack of Sleep

Not getting enough sleep wreaks havoc on your nervous system, which can alter your temperature regulating systems, Dr. Phillips said. Plus, when you're fatigued from a restless night, your metabolism works at a more sluggish pace, added Dr. Phillips, and having metabolic issues could lead to feelings of coldness, according to MedlinePlus.

How to treat it: Make sure you're getting the recommended hours of sleep each night for your age. The National Sleep Foundation states that healthy adults need seven to nine hours of sleep per night, and those over the age of 65 need seven to eight hours of sleep. Also, try sticking to a regular sleep schedule and powering off electronics about 30 minutes before you sleep.

Updated by
Grace Wade

Grace Wade is an associate editor for Health.com. While her work covers a wide range of science and health topics, she has a particular interest in nutrition, mental healthcare, the wellness industry, and the relationship between the environmental and public health. Prior to Health, Grace was an associate editor at Insider where she spent the majority of her time trying to hack Google's algorithm. She is also a fact-checker and contributor for Popular Science. When she's not working, Grace can typically be found exploring Brooklyn or hiking mountains with her film camera. Grace holds a dual degree in journalism and science in human cultures from Northwestern University with a concentration in environment, science, and society.

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Health.com uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. Assessing your weight.

  2. Mun, S., Park, K. & Lee, S. Evaluation of thermal sensitivity is of potential clinical utility for the predictive, preventive, and personalized approach advancing metabolic syndrome managementEPMA Journal 13, 125–135 (2022). doi:10.1007/s13167-022-00273-6

  3. National Institute of Diabetes and Digestive and Kidney Diseases. Hypothyroidism (underactive thyroid).

  4. MedlinePlus. Hypothyroidism.

  5. National Heart, Lung, and Blood Institute. Iron-deficiency anemia.

  6. American College of Rheumatology. Raynaud's phenomenon.

  7. Cedars-Sinai. Dehydration.

  8. Johns Hopkins Medicine. Vitamin B12 deficiency anemia.

  9. American Diabetes Association. Peripheral neuropathy.

  10. MedlinePlus. Cold intolerance.

  11. National Sleep Foundation. How much sleep do we really need?

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