Another description, copied from a famous other text book of medicine : [if you are interested see the whole description at the and of the e-mail.
………"In uncomplicated influenza, the acute illness generally resolves over a 2- to 5-day period, and most patients have largely recovered in 1 week, although cough may persist for 1 to 2 weeks longer"
During the [past] flu I "treated" most patients/families by telephone
Most people already knew what "weapons" to use and just needed some reconfirmation.
Why is the title of this story: Old books – new books?
To explain this I will now copy [and translate] from an older Dutch book of medicine  a short description of the symptoms of flu:
The disease starts mostly acute [therefore the name: grippe,griep]
[French:gripper=to attack suddenly]
The maximum fever reaches its peak in the first 3 days [40-41 Celsius],but the fever can be much lower.
The fever lasts mostly 2-3 days but it can also continue for a week.
The temperature can go down suddenly ["critically", as this is called] but it mostly goes down more slowly.
Often after 2 to 3 days the patient is fever free for a day, but thereafter the temperature rises again for 2 to 3 days.
This is precisely what we saw in many cases in this last flu and not a single modern book seems to be aware of this phenomenon, or at least none of them mention it.
[I am therefore happy with my book from 1963 [van Buchem etc]and wanted to let you know this clinical picture in case the flu still continues]
I think it is important enough to know because one could falsely start worrying if this is not known and the fever recurs.
Of course in some cases the recurring fever could be a complication, but often it is not.
The book continues with the most common symptoms like described before [cough, headache, difficulty sleeping, muscle pains, painful eye movements, can't tolerate light, etc.
It is amazing that modern text books of medicine often ignore older well established clinical symptoms.
For those interested: the whole description from a modern book.
Harrison's Internal Medicine [considered by many as the "bible" of internal medicine]
Influenza has most frequently been described as an illness characterized by the abrupt onset of systemic symptoms, such as headache, feverishness, chills, myalgia, or malaise, and accompanying respiratory tract signs, particularly cough and sore throat. In many cases, the onset is so abrupt that patients can recall the precise time they became ill. However, the spectrum of clinical presentations is wide, ranging from a mild, afebrile respiratory illness similar to the common cold (with either a gradual or an abrupt onset) to severe prostration with relatively few respiratory signs and symptoms. In most of the cases that come to a physician's attention, the patient has a fever, with temperatures of 38° to 41°C (100.4° to 105.8°F). A rapid temperature rise within the first 24 h of illness is generally followed by a gradual defervescence over a 2- to 3-day period, although, on occasion, fever may last for as long as a week. Patients report a feverish feeling and chilliness, but true rigors are rare. Headache, either generalized or frontal, is often particularly troublesome. Myalgias may involve any part of the body but are most common in the legs and lumbosacral area. Arthralgias may also develop.
Respiratory complaints often become more prominent as systemic symptoms subside. Many patients have a sore throat or persistent cough, which may last for a week or more and which is often accompanied by substernal discomfort. Ocular signs and symptoms include pain on motion of the eyes, photophobia, and burning of the eyes.
Physical findings are usually minimal in cases of uncomplicated influenza. Early in the illness, the patient appears flushed and the skin is hot and dry, although diaphoresis and mottled extremities are sometimes evident, particularly in older patients. Examination of the pharynx may yield surprisingly unremarkable results despite a severe sore throat, but injection of the mucous membranes and postnasal discharge are apparent in some cases. Mild cervical lymphadenopathy may be noted, especially in younger individuals. The results of chest examination are largely negative in uncomplicated influenza, although rhonchi, wheezes, and scattered rales have been reported with variable frequency in different outbreaks. Frank dyspnea, hyperpnea, cyanosis, diffuse rales, and signs of consolidation are indicative of pulmonary complications. Patients with apparently uncomplicated influenza have been reported to have a variety of mild ventilatory defects and increased alveolar-capillary diffusion gradients; thus, subclinical pulmonary involvement may be more frequent than is appreciated.
In uncomplicated influenza, the acute illness generally resolves over a 2- to 5-day period, and most patients have largely recovered in 1 week, although cough may persist for 1 to 2 weeks longer. In a significant minority (particularly the elderly), however, symptoms of weakness or lassitude (postinfluenzal asthenia) may persist for several weeks and may prove troublesome for persons who wish to resume their full level of activity promptly. The pathogenetic basis for this asthenia is unknown, although pulmonary function abnormalities may persist for several weeks after uncomplicated influenza.