Reviewed by Dr. Badal Kalamkar, MD on Jan. 02, 2026
Once the holidays are over, many of us feel completely exhausted. If you are struggling with feeling tired right now, you aren’t alone. Between traveling, staying up late, and the stress of family gatherings, it is normal to feel worn down once the rush finally stops.
Since the winter days are shorter and colder, it’s even easier to notice that you have low energy. But how do you know if you just need to get back into your normal routine, or if something else is going on?
According to MedlinePlus, feeling tired can be a normal reaction to stress, a lack of sleep, or changes in your daily habits. These things happen to many people during the holiday season.
However, if you still feel exhausted even after you have had time to rest, it may be a sign of a more serious health issue. In that case, it is a good idea to consult your doctor to determine what might be happening.
How Sleep, Diet, and Stress Affect Your Energy
Sleep Disruption
Sleep quality matters just as much as sleep quantity. The Harvard Health Publishing states that you may be spending enough time in bed, but fragmented or inconsistent sleep can still lead to poor sleep and fatigue.
Trying to catch up on sleep by sleeping in on weekends often doesn’t fully reset your body’s clock and can actually exacerbate fatigue on weekdays. This is one of the most common reasons people continue feeling tired weeks after the holidays.
Diet & Hydration
Food and hydration have a direct impact on how energized you feel. High sugar intake can lead to a sugar or caffeine crash, leaving you feeling even more tired than before. Skipping meals or relying on quick snacks, especially those low in protein, can make it harder to maintain steady energy levels.
Not drinking enough water is another overlooked factor; even mild dehydration can contribute to headaches, brain fog, and a lack of sleep, causing tiredness that feels difficult to shake.
Stress & Mental Load
Stress doesn’t just affect your mood; it affects your body. Ongoing stress increases cortisol levels, disrupts sleep, and contributes to stress-related fatigue. Emotional exhaustion often feels distinct from physical tiredness, but both can overlap, making everyday tasks more challenging than usual.
Could Low Vitamin D or Anemia Be Contributing?
Sometimes fatigue isn’t just lifestyle-related. Vitamin D deficiency symptoms are more common in winter due to reduced sunlight exposure. Low vitamin D levels can cause fatigue, muscle aches, low mood, and a general sense of sluggishness.
The National Center for Biotechnology Information (NCBI) explains that many people don’t realize they’re deficient until labs are checked, which is why winter fatigue and vitamin D deficiency often go hand in hand.
Another common cause is anemia. Anemia occurs when your body doesn’t have enough healthy red blood cells to carry oxygen efficiently. Anemia symptoms and fatigue often manifest as low energy, weakness, dizziness, or shortness of breath during activity.
Iron deficiency fatigue is especially common in women, people with heavy menstrual periods, and individuals with dietary restrictions or those with absorption issues.
The good news is that both vitamin D deficiency and anemia are common and easily evaluated with simple blood tests ordered by your primary care provider.
When Post-Holiday Fatigue Is No Longer “Normal”
While most post-holiday fatigue improves within a couple of weeks, it may be time to seek care if you notice:
- Fatigue lasting more than two weeks
- Tiredness that doesn’t improve with rest, better sleep, or hydration
- Fatigue that worsens over time instead of getting better
Red flags to watch for include:
- Shortness of breath
- Dizziness or lightheadedness
- Frequent headaches
- Brain fog or trouble concentrating
- Unexplained weight changes
- Difficulty getting through normal daily activities
These chronic fatigue symptoms don’t always mean something serious, but they do deserve medical attention. Listening to your body is important; persistent fatigue is often a sign that it’s time for extra support or evaluation by a healthcare provider.
How Can Zenith Primary Care Help
At Zenith Primary & Urgent Care, we make it easy to get started. Zenith Primary Care is accepting new patients. We’re here to help patients from Marlborough, Ashland, Berlin, Bolton, Framingham, Hopkinton, Hudson, Maynard, Northborough, Southborough, Stow, Sudbury, Wayland, and Westborough who are experiencing ongoing tiredness or other lingering symptoms.
Whether you need lab tests to check for vitamin D deficiency, anemia, or other causes of fatigue, or you want a same-day evaluation to discuss sleep, diet, or stress management, our team can provide a comprehensive approach tailored to your needs.
We offer same-day and next-week appointments with extended hours, so you can get care after work or on the weekend.
Take the first step toward feeling like yourself again. Call 617-500-7933 or book online through our primary care appointment scheduler to schedule your visit.
Frequently Asked Questions (FAQs)
Q: When should I see a healthcare provider for fatigue?
If tiredness lasts more than a couple of weeks or affects daily life, it’s time for a checkup.
Q: What lab tests check fatigue?
Common tests include blood count, thyroid function tests, iron levels, and vitamin levels.
Q: Can vitamin deficiencies cause fatigue?
Yes, low iron, vitamin D, or B12 can lead to ongoing tiredness.
Q: Is there a single test for fatigue?
No, labs help identify underlying conditions rather than diagnose fatigue itself.
