Are you stressed? Taking regular medication? Suffering from food allergies, or staying up too late?
It could all be contributing to a cauldron of factors that are making you feel constantly exhausted.
Auckland-based regenerative medicine expert, Dr Frances Pitsilis, says while fatigue is very common, it can also be debilitating and worrisome.
If you're familiar with that dreaded feeling of dragging your feet, Pitsilis says to start by examining your lifestyle to help pinpoint what's wearing you out.
"Are you getting enough sleep, at the right time," she says. "Are you in bed asleep by 10.30?"
Common problems that may be be contributing to fatigue are:
•Drinking too much
•Lack of exercise
•Bullying at work
•Worrying about debt
"Have a look around you and assess your situation," says Dr Pitsilis. "Start tackling these things."
Some common meds, including beta blockers for hypertension, and statins used to control cholesterol, can cause fatigue.
Dr Pitsilis, who featured on the popular TVNZ show, Is Modern Medicine Killing You?, says sleeping pills and anti-depressants can also contribute to tiredness.
Simple deficiencies like low levels of magnesium, iron or vitamin B12, can make you feel exhausted, says Pitsilis.
"Women of reproductive age, as well as small children, are most likely to suffer from an iron deficiency", she says.
Symptoms of a magnesium deficiency - a vitamin that helps you get to sleep, include leg cramps, twitchy eyes and ringing in the ears.
"A very important thing to look at, that is often not tested, is vitamin D," says Pitsilis.
"Believe it or not, it helps with virtually everything in the body; sleep, energy, heart, brain. If you have an indoor job, or live in a cooler area. Get your vitamin D tested."
For some people, gluten and dairy wreak havoc with energy levels, says Dr Pitsilis.
"I think most people should avoid eating gluten," she says. "We didn't develop with gluten from cave man times, so most of us will end up not coping very well with it."
If you're keeping an eye on your food intake in order to identify allergies, bear in mind that the effect of a food intolerance can be delayed by 3-4 days.
"Always consider this if you've worked in an industrial environment, and associated with heavy metals like lead, mercury, and cadmium," says Dr Pitsilis.
People who have worked in a factory with chemicals, or even a dental environment where mercury has been used, could be tired due to levels of chemicals in the body.
Long term factors
Long term causes of tiredness can include chronic fatigue syndrome, fibromyalgia, autoimmune disease, heart disease, or a neurological disorder, all of which should be treated under the guidance of a health professional.
"See your doctor to rule out serious causes for fatigue, says Pitsilis, "don't just put up with it."