Can halitosis lead to a sore throat?

It depends: If the halitosis is due to a periodontal condition, it could lead to a sore throat since the main bacteria for periodontal disease is streptococcus mutans, the same that causes strep throat when out of balance.

Nope: Group a streptococcus pyogenes causes strep throat, s. Mutans is the major cause of plaque and dental decay, but doesn't cause strep throat. Halitosis can occur because of a throat, nasal, gingival or sinus infection, not the other way round.

Strep Throat or : Other throat infections could cause halitosis. Bad breath may be caused by smoking, dry mouth (due to medications, ^ mouth breathing or salivary gland problems), gum infections, poor dental hygiene, certain foods (like garlic, curry, fish oils or onions), sinusitis, post nasal drip, infections in the mouth, bronchitis, lactose intolerance, gerd, improperly cleaned dentures, braces ; retainers. See.