October 25, 2026·4 min read

Good Days and Bad Days: Why Concussion Symptoms Come and Go

Feeling better one day and worse the next is common after a concussion. Here's why symptoms fluctuate, what triggers bad days, and how to pace your recovery.

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"I was fine yesterday. Why am I worse today?"

It's one of the most common things we hear from people recovering from a concussion. You have a good day and start to feel like yourself again, then the next day the headache is back, your concentration is poor, and you wonder whether you've gone backwards.

Usually you haven't. Concussion recovery rarely moves in a straight line. Symptoms rise and fall from day to day, and sometimes within the same day, even when the overall trend is improving.

Why symptoms fluctuate

After a concussion, the brain's energy supply and its ability to manage demanding tasks are temporarily reduced. Think of it as a smaller battery that drains faster and takes longer to recharge. On a good day, you may feel close to normal until you use more energy than you have, and then symptoms catch up with you, sometimes hours later or the next day.

Other systems commonly affected by concussion also change from day to day:

  • The neck. Stiffness and muscle tension can drive headaches that vary with posture, stress and sleep. See neck pain after concussion.
  • The balance and visual systems. Busy environments, screens and travel can overload them on some days more than others.
  • Sleep and mood. A poor night's sleep or a stressful day lowers tolerance for everything else.

Common triggers for a bad day

Looking back at the day or two before a flare often shows a pattern. Common triggers include:

  • Doing too much on a good day, the "boom and bust" cycle described below;
  • poor or short sleep;
  • long screen sessions or a lot of reading;
  • busy, bright or noisy places such as shopping malls, restaurants and arenas;
  • stress, worry or emotionally demanding days;
  • skipped meals, dehydration or alcohol;
  • a cold, flu or other illness;
  • long drives or travel days.

The boom-and-bust trap

The most common pattern we see is boom and bust. On a good day, people catch up on everything they've been putting off: work, errands, exercise, housework. Symptoms then flare, they need a day or two to recover, and the cycle repeats.

Over weeks, boom and bust can make recovery look much slower than it is. The fix is pacing.

How to pace your recovery

  • Stop before symptoms peak. If an activity is pushing symptoms up, stop while they're mild rather than pushing through to the point you need a day to recover.
  • Keep good days steady. On a good day, do a little more than usual, not everything at once.
  • Break tasks up. Two 30-minute blocks with a rest between are often easier than one hour straight.
  • Keep light activity going. Gentle walking and light exercise within your tolerance generally help recovery, while complete rest beyond the first day or two usually doesn't.
  • Track the weekly trend, not the daily one. A simple symptom diary can show that your bad days are less severe or less frequent than they were two weeks ago, even if today feels rough.

When to seek help

Fluctuation on its own is normal. These patterns suggest you'd benefit from an assessment:

  • symptoms aren't improving overall after two to four weeks;
  • bad days are becoming more frequent or more severe;
  • you can't increase activity without a lasting flare;
  • particular symptoms, such as dizziness, headaches or brain fog, are dominating your days.

Seek emergency care straight away for a severe or rapidly worsening headache, repeated vomiting, increasing confusion or drowsiness, weakness or numbness, slurred speech, or a seizure.

How treatment helps

Concussion physiotherapy aims to find out what is driving your symptoms and treat it, rather than waiting it out. At Burlington Concussion Clinic, that can include:

  • treating the neck when it's contributing to headaches;
  • vestibular and eye-movement exercises for dizziness and visual strain;
  • a graded exercise plan to rebuild tolerance safely;
  • a pacing plan built around your work, school and family life.

If your good and bad days aren't settling, book a concussion assessment online or call us at 905-635-5711.

This article is general information and doesn't replace individual medical advice.

Neural pathways representing concussion rehabilitation

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