Headache, nasal congestion and fatigue in the evening

What you're describing may be consistent with an upper respiratory tract infection (cold), allergic rhinitis, or sinusitis; headaches can also be caused by tension-type headaches. Evening fatigue may be related to both the infection/allergy and poor sleep quality.

A few quick questions for you:

• How long has it been going on? Do you have a fever, sore throat, or cough?
• Pain and pressure in the face, especially over the cheekbones, toothache, or a decreased sense of smell?
• Do you have a runny nose? If so, is it clear or yellow-green?
• Where is your headache most common (forehead, around the eyes, or the back of your neck)? Do you experience light/sound sensitivity or nausea?
• Do you have any allergy symptoms such as itchy, watery eyes, or sneezing? Do they increase or decrease with the season/environment?
• If you use a nasal decongestant, how long have you been using it?
• Have you been exposed to or tested for COVID/the flu?
• How is your sleep quality? If you use CPAP, are the humidifier settings and mask comfort adequate?

Things you can do at home for now:

• Rest, plenty of warm fluids, and nasal irrigation with isotonic saline/seawater 2–4 times a day.
• For nasal congestion and sinus pressure, use an intranasal corticosteroid spray (e.g., mometasone or fluticasone) 1–2 times a day, regularly for at least 1–2 weeks. The effects begin within a few days.
• If you have allergy symptoms, use a single dose of a non-sedating antihistamine (e.g., loratadine, fexofenadine, or cetirizine during the day).
• You can use a topical decongestant spray (e.g., oxymetazoline/xylometazoline) for short periods (up to 3 days); longer use can cause "rebound congestion." Be careful with oral decongestants (pseudoephedrine), as they can cause hypertension, palpitations, and insomnia.
• Choose paracetamol for pain relief. If necessary, take short-term ibuprofen, unless you have stomach or kidney problems.
• Take a warm shower/steam inhalation and sleep with your head slightly elevated.
• If you use CPAP: Turn on/increase the volume of a heated humidifier, perform a nasal wash before bed, check for mask leaks, and clean regularly. For severe congestion, a full-face mask may be more comfortable for short periods.
• Smoking increases nasal congestion and headaches; reducing/quitting smoking significantly relieves symptoms.

When to see a doctor?

• If it persists for more than 10 days or worsens significantly after 5–7 days.
• If you develop a fever over 38.5–39°C, severe one-sided facial or dental pain, purulent discharge, and loss of smell.
• If you experience swelling/redness around your eyes or vision changes.
• If you experience neurological symptoms such as sudden onset of the "worst headache of your life," neck stiffness, confusion, weakness/numbness, or slurred speech, seek immediate medical attention.

You can follow up and consult the following specialties:

• For initial evaluation and nasal and sinus issues: Ear, Nose, and Throat.
• If an allergic cause is suspected: Immunology and Allergy Diseases.
• If your symptoms are disrupting your sleep quality or you are experiencing device problems: Sleep Disorders or Pulmonology.
• For a general evaluation: Internal Medicine.

If you answer my questions, I can provide more detailed guidance. I hope you get well soon. I am not a doctor, and this is not a medical diagnosis.